I stare stupidly at it. It’s nothing much to look at. It’s only a small pile of clothing: the shorts and tank top that I wear in bed, which I have thrown on to the floor before getting into the shower. I stare stupidly at the clump because I can’t pick it up. It’s astonishing that I managed to shower, because I know already that this is a bad day, one when I feel assaulted by my hormones, which I picture as small pilots in those huge Star Wars armoured beasts that turn me this way and that, implacable. On this morning, I wake up with fear in my stomach – fear of nothing – and I know it will be a bad day.

For a while, I thought I could predict these days. I have had practice. This is my second menopause: the first was chemically induced seven years ago to treat my endometriosis, a condition that has riddled my insides with adhesions of endometrial tissue, and stuck my organs together. The adhesions are exacerbated by oestrogen; the drug switched it off. (The same drug can block other hormones and is also used to treat paedophilia and prostate cancer.) I hated that menopause. It was a crash off a cliff into sudden insomnia and depression, and a complete eradication of sexual desire. “The symptoms will last six months,” said the male ob-gyn, with a voice he thought was kind but that sounded only casual. They lasted far longer. The nurse giving me the first injection said, “He keeps prescribing this stuff, but women hate it.”

This menopause is the natural one. I’m two years in. It doesn’t feel natural. It feels like a derangement. With each menopause, I have chosen to take hormone replacement therapy (HRT). The first time because I wanted my sleep back. This time because I spent a year researching menopause for a magazine article, and because I have weighed the risks and judged them acceptable, and because I know what happened last time, when I was broken. The two occasions when I asked for HRT are the only two on which I have cried in a doctor’s office.

Every Wednesday and Saturday, I take two 100mg transdermal patches of estradiol (a form of oestrogen). I fix them to my abdomen, swapping sides each time. They never fall off, though I go running for hours at a time and sweat. This is the maximum dose of oestrogen, and it took about a year for me to understand that I needed this amount – a year of peeling skin, sore tendons, poor sleep, awful sadness, inexplicable weeping and various other “symptoms” of menopause that you can find listed if you look beyond the hot flushes and insomnia. Oestrogen is more powerful and more wide-ranging than is assumed, and its removal or diminishment brings effects ludicrously understated by “the change”.

A friend gave me access to her university library and I start to swim among papers, sometimes floundering. I learn that oestrogen is a gonadal steroid produced by the ovaries, and essential to female reproduction. It is a sex hormone but – it is now known – far more besides. There are receptors for oestrogen all over the body. In the brain, the densest amounts are in the amygdala, the hippocampus and the hypothalamus. Oestrogen influences serotonin, dopamine, glutamate and noradrenaline. It is involved in cognitive function. Its diminishment can impair verbal dexterity, memory and clarity of thought. Recently, scientists discovered that oestrogen is also produced in the adrenal glands, breasts, adipose tissue and brain. This is astonishing. But so is the extent of the unknown.

Perimenopausal women (whose periods may be irregular, who have symptoms, but who are not yet postmenopausal) are twice as likely to have depressive symptoms or depression than premenopausal women. Perimenopausal women who were vulnerable to depression during the menstrual cycle are more susceptible to depression when they enter menopause or its hinterlands. This is accepted, but there is disagreement about how to fix it. Antidepressants often don’t work. Studies show both success and failure when women are given oestrogen to counter depression. Controversy exists over whether the menopausal transition is a risk factor for the development of depression, I read. And, I think, the person who wrote that has probably never been on a menopause forum, where women’s stories and pain would make me weep, if I didn’t feel like weeping already, from menopause.

Because I have a womb – though it is likely of no use for fertility, thanks to the endometriosis – I also take progesterone for 10 days a month. This induces the womb to shed its endometrium, which may otherwise thicken to cancer-risky proportions. So I still bleed, and choose to. I knew from my research that the gentlest version of progesterone is micronised, something that my doctor had to look up. I didn’t know that taking it orally, as I had for many months, would bring me profound sadness, fatigue, weight gain, awfulness. That wasn’t something I discovered in my research, and no one told me.

I can’t pick up the clothes. I can’t explain the granite of that “can’t”, the way it feels impossible to beat. Look at me looking at the pile and you will think: Just pick it up. For fuck’s sake. But I don’t. I look at it, and the thought of accomplishing anything makes my fear and despair grow. Every thought brings on another, and that prospect is frightening. I feel stupid and maudlin and dramatic. A privileged freelance writer who does not have a full-time job that requires her presence in an office and can be indulgent of what the medical profession calls “low moods”. In fact, plenty of menopausal women leave their jobs, endure wrecked relationships, suffer and cope. Or don’t.

The phrase “low moods” is belittling. My depression is not simply feeling miserable or glum. I know what that feels like. I know that that can be fixed by fresh air or effort. This depression is dysfunction, derangement.

I feel terrified. I have no reason to feel fear. But my body acts as though I do: the blood rushing from my gut to my limbs in case I need to flee, leaving the fluttering emptiness that is called “butterflies”, though that is too pretty a description.

Still, I set off on my bicycle to my writing studio. I hope I can overcome the day. I always hope, and I am always wrong. A few hours later, I find myself cowering in my workspace, a studio I rent in a complex of artists’ studios, scared to go downstairs to the kitchen because I can’t bear to talk to anyone. I have done nothing of use all day. Every now and then, I stop doing nothing and put my head in my hands because it feels safe and comfortable, like a refuge. I look underneath my desk and think I might sit there. There is no logic to this, except that it is out of sight of the door and no one will find me.

Still, when the phone rings, I answer it. It’s my mother calling. I am hopeful that I can manage it and mask the panic. I haven’t spoken to my mother for a few days, and would like to. It goes well for a few minutes, because I’m not doing the talking. Then she asks me whether I want to accompany her to a posh dinner, several weeks hence. She doesn’t understand when I ask to be given some time to think about it. “Why can’t you decide now?” I say it’s one of the bad days, but I know this is a mixed message: if it’s that bad, how am I talking on the phone and sounding all right? Because I am a duck: talking serenely above, churning below, the weight on my chest, the catch in my throat, the inexplicable distress. I try to explain but I’m also trying hard not to weep, and so I explain it badly.

Hormone replacement therapy tablets. Photograph: Alamy

She doesn’t understand. This is not her fault. She is a compassionate woman, but she had an easy menopause, so easy that she can say, “Oh, I barely remember it.” She doesn’t understand depression, though both her children experience it, because she has never had it. “But you sounded well,” she says, “I thought you were all right.” Now she says: “I don’t understand how your not being well is stopping you deciding whether you want to go to dinner.” Because it is a decision, and a decision is too hard, requiring many things to happen in my brain, and my brain is too busy being filled with fear and panic and black numbness. There is no room to spare.

I hang up. I stay there for a while, sitting on my couch, wondering how to face opening the door or leaving my studio or cycling home. All these actions seem equally impossible.

On days like this, there are only two places to be. One is in my darkened bedroom with my cat lying next to me. On days like this she takes care to lie closer to me than usual, because she knows. Maybe my darkness has a smell.

The other place to be is in unconsciousness.

These are the safe places because everything is quiet. It is on the bad days that I realise what a cacophony of impressions we walk through every day, and how good we are at receiving and deflecting, as required. Every day, we filter and sieve; on the bad days, my filters fail.

I sometimes call these bridge days, after a footbridge near my studio that goes at a great height over the busy A64 road. On days like this, that bridge is a danger for me. I am not suicidal, but I have always had the urge to jump. This is a thing with a name. HPP: high place phenomenon. The French call it l’appel du vide. So very Sartre: the call of emptiness. The A64 is the opposite of emptiness, but still, it is a danger. Today I don’t have the filter that we must all have to function: the one that stops us stepping into traffic or fearing the cars or buses that can kill us at any time.

I avoid the bridge. I cycle home, trying not to rage at drivers who cut me off and ignore me. I have no room for rage along with everything else. Thoughts that would normally flow now snag. Every observation immediately triggers a negative thread, a spiral and a worsening. On a good day, I can pass a child and a mother and think: how nice. Nothing more. Fleeting. Unimportant. On a bad day, I see the same and think of my own infertility, how I have surely disappointed my mother by not giving her grandchildren; how it is all too late, and what have I done with my life, and my book will be a failure and today is lost and I can’t afford to lose the time. It goes on and on. Snagging thoughts that drag me down, that are relentless.

When I get inside my house, I cry. I try to watch something or read, but nothing interests me. This is another symptom of depression, called anhedonia: forgetting how to take pleasure. The best thing to do is sleep away the day, as much as I can.

Toward evening, I begin to feel a faint foolishness. This is my sign: embarrassment. Shame at the day and at my management of it. When I am able to feel that and see that, I am getting better. Now I manage to watch TV, though only foreign-language dramas. Foreign words go somewhere shallower in the brain; they are less heavy. But soon I switch it off. I don’t care about the plot. I don’t care about anything. I take a sleeping pill to get the day over with, so the better next day can begin.

Twenty-four hours earlier, I had been wearing a Santa hat, running for five miles through icy bogs on a Yorkshire moor, happy to be doing that for fun, happy to be alive.

April 4. Sleep mostly OK; a few days of melatonin after stopping progesterone. Last night I was exhausted, but slept badly. Mood difficult but not dreadful. Angry and irritated. No bleed after progesterone. Peeling skin. Weepy and panic now. Can I face people?

Depression, wrote William Styron, is a noun “with a bland tonality and lacking any magisterial presence, used indifferently to describe an economic decline or a rut in the ground, a true wimp of a word for such a major illness”. It was pioneered by a Swiss psychiatrist who, Styron thought, perhaps had a “tin ear” and “therefore was unaware of the semantic damage he had inflicted by offering ‘depression’ as a descriptive noun for such a dreadful and raging disease”.

“Black dog.” “Walking through treacle.” “Low moods.” Nothing I have read of depression has conveyed the crippling weight of it.

I do not have depression according to most authoritative clinical definitions of the condition. Depression is a long-term chronic illness. Mine is unpredictable, and before I got my HRT dose right, it lasted weeks at a time; but usually, these days, it lasts no more than 24 hours. My now-and-thens do not qualify as a disease. I do not count as depressed. Instead, I am one of the women of menopause, who struggle to understand why we feel such despair, why now we cry when before we didn’t, why understanding what is left and what is right takes a fraction longer than it used to: all this is “low mood” or “brain fog”. These diminishing phrases convey nothing of the force of the anguish or grief that assault us.

I have never been sunny. People who can rise from their beds and see joy without working at it, they have always been a mystery. I still feel guilty for once asking a cheery person, early in the morning, why he was so happy – I made it sound like an accusation. Cheeriness always seems like an enviable gift. I have always been susceptible to premenstrual upheaval: two days a month when things feel awful, as though they have never been anything else. I endured them. Now and then, there have been therapists and antidepressants, and, for the last few years, running in wild places, which is the best therapy. I have managed.

Then I became a menopausal woman. In the eyes of evolution, that makes me a pointless person. I can no longer reproduce, if I ever could. The grandmother theory of menopause – that women live beyond their reproductive utility in order to care for grandchildren – doesn’t persuade me. Also, I have no grandchildren. I cannot account for how awful menopause can be, unless I think that we were not meant to survive it.

Thursday 14. Removed old patch, added half a new one. Mood immediately plunged. Awful: anhedonia, anxiety, panic, weepiness. I still ran, but stopped to cry in the middle. So sick of this, and I can’t work.

For months, I resisted HRT. I endured as my periods got erratic, as I lost my ability to sleep through the night, as my temperature rose furiously at unpredictable moments.

I woke up in the night boiling hot and pouring sweat. I use “pouring” deliberately because I was drenched. Sometimes, I woke up freezing because I was covered in cold sweat. Every athlete knows to change clothes as soon as possible because sweat chills so fast. Every night, it was as though I was running several races. I woke up fatigued, stinking and angry that something so common, something that affects millions of women, is still such a medical mystery. Why do we get hot flushes? We don’t know. Why is sleep broken? We don’t know. Why are we the only creatures to get menopause apart from two types of whales? We don’t know.

My doctor prescribed a low dose of HRT and a visit to a specialised menopause clinic, of which there are far too few. My menopause doctor prescribed a higher dose of HRT, but the symptoms continued, and were far more numerous than the hot flushes and insomnia to which menopause is usually reduced in common perception. I made a list: at various points, my skin peeled, my ears rang with tinnitus, my posterior tibial tendon swelled, my lubrication disappeared, my eyes dried so it felt as if I had grit in them, my jaw locked. The menopause doctor prescribed a still higher dose, and still they came. Finally, I sat in her office and said I couldn’t think straight.

Photograph: Nick Veasey/Getty

I felt like I was going mad. I became clumsier. I forgot everything: names, events, appointments. My partner began to say, carefully, too often, “Yes, you’ve mentioned that,” in the same way I used to say it to my dad when he had dementia. The menopause doctor said, “This is just your age.” The year before, aged 46, I had had no brain confusion. Forty-seven, and menopausal, I did. And she was a specialist. I never went back.

I paid to see a private menopause specialist who immediately said I could be on the maximum dose of oestrogen, that she couldn’t understand why no one had told me that taking progesterone orally causes many women troubles such as profound fatigue and depression, or that I could take it as a pessary in half the dose for less of the time, which would be better (it is). She also prescribed testosterone, a clinical decision that is controversial in the small circle of medical professionals who take an interest in menopause. It is unnecessary, say sceptics, because the ovaries produce enough testosterone – and mine are still there, though sputtering into dysfunction. But it can help, say others, because testosterone can lift energy and mood. Perhaps I would get a libido back. Perhaps I would remember what desire feels like, rather than looking at my partner and thinking how lovely he is, but distantly, through a glass pane, as if that thought had nothing to do with me.

I took my new boxes of patches, a pump gel of oestrogen to top up with on the bad days, my precious testosterone, and went home with hope. It took months, but things stabilised. Now, there is never more than one bad day at a time. On the good days, I am at peace with my age, with what I have done, with who I am, menopausal or not. I delight in what I can do, and when I run, I hurtle headlong down a steep descent with the joy of a child, aged nearly 50. But on other days, that woman seems like someone else.

Monday 25. First morning I haven’t felt dread and weepiness. Not giddy like before, but like things are possible. But also scared of mood flipping – and it did. Horribly. Weepy, panicking, total anhedonia. I haven’t left the house. At 3.30 I went to bed and woke up at 6. I feel profoundly sad, black, AWFUL. Did it all change after I drank coffee? Tuesday 26. No coffee. Panic, dread, weepy. Can’t focus, can’t wash up.

I grasp for reasons. I look for patterns. I keep a diary for 18 months. If I can understand the patterns, I can predict the bad days and allow for them. I can plan for them. Tom Cruise in Minority Report had “pre-crime” to prevent and disrupt future criminal threats. Perhaps I can have pre-depression. For many months, I think that the bad days come when my oestrogen dips on the last day before I get new patches. I stop scheduling things on Mondays and Fridays. But then the pattern changes, so I know it never was a pattern. Sometimes it’s a Tuesday. Sometimes, a Sunday. I can’t tell. I give up the diary.

I try to take control by being less embarrassed. Once, when I still had flushes and was out at dinner, I got out my fan and a relative said: “Must you?” I don’t understand this reaction. People are not mortified by cancer patients on chemo who sweat and use fans. Is it because menopause is to do with periods? Is it because women’s health must be hidden and quiet? Is it because women do hide it? I can’t think why the irregularities of the hypothalamus should be socially unacceptable. I kept using my fan for as long as I needed to, though I felt faintly uneasy.

The only acceptable place for menopause is in menopause jokes. The humour that masks distress and shame. The woman in a meeting who laughs off her sweating, who talks of “power surges”. The comedians and their mothers-in-law and their hot flushes. What if it came out of jokes and into accepted conversation?

For many months, I told people I was “unwell”. Not crippled, not weeping, not disabled. “Unwell.” The implication: that there is something physically wrong, a proper illness. What if I told everyone I had a severe headache? They would understand. Then, one day, as I sit at my computer and think of my writing deadline and feel despair, I try to read medical literature and instead put my head in my hands. I decide to write to the commissioning editor, even though we have not worked together before and this may form her opinion of me, and say: I can’t function today. I can’t write. And it is because of depression. Please give me leeway. It shames me to write it, but I do. And I do it again, when needed. So far, every response has been profoundly kind. I should have done it sooner.

Mental illness. Such an odd concept. How strange to put a division between mental and physical illness, as if the brain is not in the body. As if emotions are not regulated by the brain. As if feelings are not linked to hormones. And still mental illness is put in a different category. Easier to fix, to underfund, to sweep into the dark corner of the unspoken. Imagine the contrary. Broken your ankle? Cheer up. Third-degree burns? Chin up. Think yourself better, you with your chronic lymphocytic leukaemia. Smile.

May 4. Finally felt better yesterday. Tweeted fury about BBC menopause doc and all its talk of “low moods”. Messaged with a doctor who thinks 50mg of estradiol is too low and particularly for someone who was prone to PMT. She also thought I should try testosterone. Went downstairs and put another patch on. Retroactively furious with doctor for sticking so firmly to dose, but maybe I played down the depression. Today I slept well. Mood good. A feeling in my stomach that is positivity, like I can do things.

I wake gloomy, my head foggy apparently from just one glass of prosecco the evening before. The room is hot, the city noises are infuriating. I put new oestrogen patches on my abdomen. I smear testosterone gel, two pea-sized globs, on my inner thighs. I go through the motions of other activities and wait. Half an hour later, as I am walking to the station, I feel a quiet flood of good mood. It feels as though the oestrogen is lifting me slightly. I picture a tide floating buoys higher and higher in a harbour. Oestrogen is hefting and hauling me out of depression, for today.

This is my theory. It is unproven, according to the literature. I wish the urge to better understand the extent of oestrogen’s reach, and the devastation its fluctuation can bring, had happened decades ago. There has been more research in recent years, but I doubt that the driver for this knowledge is how poorly menopause is treated or understood; it’s probably that oestrogen is implicated in higher rates of Alzheimer’s disease in postmenopausal women. There is money in Alzheimer’s, but not in making women’s lives better.

Friday 22. Woke up at 10. Awful, awful, awful. Got up at 12 and ran 10 miles, got back and burst into tears. Profound sadness, depression, weepiness. One of the worst yet. Panic at night.

My mother says, the day after another bad day: “I feel so awful for you. Why can’t they fix it?” They are doing all they can, I say. I don’t really believe this. The trouble with women is we cope. We always do.

I keep fit. I gave up alcohol for months, reasoning that it plunges me into depression the next day – and I can produce those days all on my own without paying money to make them happen. Over the years, I have taken citalopram, sertraline, black cohosh, red clover, omega 3, magnesium, iron, vitamin D. For a while, I saw a serene herbalist, who mixed dark potions and told me I should eat chickpeas and tofu to get their phytoestrogens to bind to the receptors all over my body. Many perimenopausal women with depression are prescribed antidepressants. I hope theirs work, as mine did nothing. I know the iron helps, and I think the magnesium does, too, because when I forget to take it, I start to feel stupider.

In scientific papers, researchers argue about whether women feeling depressed in menopause (pre-, peri-, post-) are actually just experiencing the ups and downs of life. We are brought low, they reason, by the hot flushes and sleeplessness, not by hormonal fluctuations. Or we are diminished by life. At that age, I read, women may have ageing parents to care for; grown children and an empty house; empty marriages. Their depressive symptoms are a mourning for who they were and what is to come. They have what is called “the redundancy syndrome”. It’s just coincidence that they are also menopausal. “Research has found,” I read, “that depressed mood and depressive disorder in middle-aged women are related less to menopause than to the vicissitudes of life.”

I bristle at this. Although I wonder. I remember a month in France when I had not a single bad day. I notice that my mood lifts once my book is written and its huge pressure is also lifted. I wonder: is my problem not menopause-specific depression, but that the removal of oestrogen leaves me less protected against my natural lows? This theory lasts until the next bad day, when I remember how elemental it feels.

May 2. I slept fine and took no pills, but today was the same. Sad, weepy, furious. I can interact with people, but in-between is awful. I went home at 3 and went to bed until 6. I hate this.

Today. Today is a decent day. It has taken me months to write this essay, because when I am bad, I can’t write, and when I am not, I don’t want to remember. Tomorrow? My menopausal status is being masked by HRT, so I won’t know when I become postmenopausal until I dare to stop my artificial bolster of hormones. My postmenopausal friends tell me everything is better on the other side. I want to believe them, and ask my doctor, a young woman half my age, when I can stop taking HRT and what will happen if I do. She says: “Four years? That’s about right.” Stay on HRT for four years, wean yourself off it, and then see. This means that in order to get off HRT I have to plan for a time in my life when I can risk being brutalised by depression and insomnia for weeks at a stretch, when I might crash to the bottom again. Even on a good day, I think that time will be never.

This is an edited version of a piece that first appeared on the New York Review of Books Daily

• Follow the long read on Twitter at @gdnlongread, or sign up to the long read weekly email here.