Wind back 12 months.

"I don't know who I am, who are you?" is looping around and around and around in my head. I write it down on a post it note and post it to my Instagram. None of the answers that come back help. It doesn't interrupt the loop. Around and around it goes.

The therapist tries. To her credit, she accepts I am not stupid, just broken. I tell her I've done CBT and currently it's like posting a paper origami boat into a tsunami and hoping it will help. My mind is a tsunami. It is sucking everything, absolutely everything, into a massive wave and then that wave is crashing down over me. It feels as if pieces of my brain were literally being swept up, churned into a seething mess and then hurled down onto a stone beach where they smash into pieces.

I am in a constant state of terror. I don't know it at the time but I've almost literally terrified myself to a stand still. I can't walk. I can't talk. I can't verbalise or articulate or write or tweet. I am literally a piece of meat. The electrics have either gone out or there is a super cell stuck in there, stuck in my brain.

Underneath all of this, of course, is the bubbling narrative of failure. I failed. I let every one down. I was supposed to be kicking ass and instead I was quietly dying, all the systems going off line, giving up, giving in, all the fight sucked out of me by cognitive absence.

That sounds like depression, doesn't it? Doesn't it just. It's not. It's far more complex than that. I, it turns out, am far more complex than that.

Depression sucks everything from you. And the state of this being is similar for most of those who suffer from it. @markoneinfour has kept me anchored without even knowing it. But the cause of the depression, I believe, is different for everyone. Everyone has different triggers. Everyone suffers but everyone I think also suffers differently. I am thankful, so very thankful to my GP for understanding that sometimes she has needed to leave me alone, sometimes she has needed to let me come to her of my own accord and ask for pills, and sometimes she has said the wrong thing and I've backed away for a bit, needing time to think and work out and rationalise.

So why the terror, I suppose is the question. What triggered it? And I'm sure the easy answer would be GDS, would be travelling up and down the country every single weekend, living in two places at once. That answer would make a lot of people happy. But it's not the truth.

When I was 12 years old my world changed. I got my first period. My mum didn't talk to me about periods. She didn't talk to me about anything. She managed to apologise earlier this year for not being able to cope with being a mum to two people. And that I'd been the one without a mum, essentially, came as no surprise to either of us. The apology came as a massive shock. I suspect to both of us.

The point? I don't ask for help. There has never been anyone to ask for help from and so I have essentially worked through my life with the same attention to detail and focus that I apply to everything. It makes me selfish. It makes me focused. It makes me stupid and oblivious to the disintegration of my own state of mind. I am so close to the problem I can neither see it nor feel it.

Normally, my other half can spot when problems are happening and it's a standing joke that he acts as my personal people interpretation module. I didn't have that in London. Oh boy did I not. I should have worked it out when a colleague decided the only way to tell me how fucked off she was with me was to write me a letter telling me then reading it to my face. I should have worked it out when I couldn't find anyone in the 200 people office, instead needing to gchat people to ask them where they were. I should have worked it out when the amount of meetings I had in the day inversely affected what time I needed to go to bed (9pm most nights). I should have worked it out when I lost my appetite. When I couldn't sleep.

Some of those things sound like depression. But not all. Not all of them by any stretch of imagination. And the penny didn't even drop when I took the 'Reading the mind in the eyes' test and got something like eight out of 40 and I guessed those eight. And having to look at nothing but eyes for 20 minutes made me feel sick to my stomach and quite panicky. Not when a colleague sat me down and asked me if I didn't realise I couldn't deal with people sitting opposite me and interacting with them and felt much more comfortable sat next to people and even my hobby involved talking to people next to me – riding bikes.

It's all so glaringly obvious to me in retrospect. Not to others though. "I am autistic," I say, and they say, "no you aren't, you can't be".

Well here's the thing. I am. The 45/50 says I am. The trained qualified clinical psychologist says I am. But truth be told. Tony Attwood and his absolutely mind-blowing explanations of how autism, and especially Asperger's, affects women rather differently than men told me I was.

I've been diagnosed with autistic spectrum disorder, depression and anxiety in the space of six months. "I don't know who I am, who are you?" still runs through my head. But alongside it runs something else: an understanding, an ability to cut myself some slack. The person who read me the letter didn't understand why I was coming across one way when I was intending to come across in a completely different way. My boss didn't understand. No one understood, least of all me. It turns out, in the end, that the prevailing theory is that I am allergic to people, currently. If I spend any time with anyone but my other half, I pay for it. I am exhausted, often for days after. We think that this is because I am doing so much processing, trying to fit in and not stick out as being different that I've worn out my brain a bit. While I was in London I was trying to do the following:

• Process the interaction scripts for 100+ people

• Remember the faces and names of ditto

• Get myself dressed and out of the house looking presentable (not smart or anything, just enough not to raise too much comment)

• Eat properly when I can't cook

• Sleep properly and enough to recover from exhausting days when sleep has always been an issue

• Manage a workload that was at the high end of the scale

• Attend at least three meetings a day at one point, resulting in high intensity interaction for three hours every day

• Remember pretty fundamental processes like going to the loo, drinking enough in the heat, etc.

What I'd like you to do is think how your friend's daughter/son who is autistic would manage all that. Now I want you to imagine you don't know there is anything wrong with you and you're sat in the absolute best job on earth that hundreds of other people want and you don't know why you're struggling. Now I want you to imagine your support network has disintegrated and you're miles from your boyfriend and you hate speaking on the telephone with a passion unrivalled because you don't know when you're supposed to speak in a conversation even worse than when you're face to face with someone.

Body language. Knowing when to talk in conversations, knowing when to shut up, when to leave, when to arrive, when to leave someone alone … yep, I bet some of you are nodding your heads right now.

The simple fact is, I was burning through massive amounts of processing power, just trying to look like all of you. There was nothing left to do my job. I remember someone commenting loudly in the office that I looked exhausted every evening.

Well I was. This is why. I was, as servers go, running at max. The line was at the top all the time. It was so bad by the end I couldn't drop out of fight or flight. I'd been in it for months by that point. It was normal. I burned through all my reserves, I burned through everything. Right down to the bone.

And then I snapped.

So if you don't mind, considering where I've been, how I've felt and what I've learned, don't reply to this post with, "You can't be autistic".

I can, and I am. And I am slowly but surely learning how to not spend my entire waking existence pretending I am just like you. I am not just like you. My brain is not like yours. I do not see the world the way you do. I like that. I don't care if you think this is awful and a waste of talent and time. I couldn't give a flying squirrel.

I am autistic and I am proud of it. I see such beauty because of it. But I also see such agonising sorrow. So yes I have depression. Is it any surprise? But I also have hope. I have some slack with which to cut myself. I have a thing to choose to disclose, and I choose to disclose it here. If you think you can still work with me and understand that this actually changes nothing in terms of my intelligence, my speed, my pattern matching, my life loving, question asking joy, thank you.

If you don't want to know me, or talk to me, or work with me any more, then I am sorry. Sorry for you. Good bye.

This post first appeared on Louise Kidney's personal blog, A Shiny World

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