A month ago, I decided to go out and find all my ex-boyfriends, to see what has happened to them, and to conduct a live-action autopsy of our relationships. I was so excited: I would have an excuse to ring them all up and stalk them. I'm back! I'm a journalist! And, contrary to the expectations of everyone who knew me before I stopped drinking six years ago, I am alive!

There are 15 I remember, and 10 I can name. First there is David, whom I knew when I was 13. I used to stand at parties drinking vodka, like a small Judy Garland, drooling at his Aryan blondness. Google gave me his phone number, at a law firm in the City. "It's an interesting idea... can I call you back?" he said. He never did.

Oliver, whom I dated at Oxford, actually screamed at the suggestion. "No! No! No! I don't want to do that. Don't ask me again. Ever." So how about Alan? He blacked my eye at university because I was sleeping with his friend. He whispered down the phone that he never wants to talk about Oxford again. Small twinges of guilt began to seep into my jolly game. Had I hurt these men?

I will have to dive deeper, deeper than I want to. So I look for Adam on the internet, and within a week we are lunching at a cafe. I met Adam when I was 14 and gadding around town with a would-be party girl called Amanda, who was terribly embarrassed about the fact that her father was a taxi driver. I was terribly embarrassed that my father was a dentist. So we got on. One night in a pub in Camden, we bumped into Adam.

He was 19 and tall and gaunt and looked as if he had escaped from a hospice. I thought he was cool because he smoked pot and lived in Muswell Hill, so I mooned around after him. I was from Norbiton - a satellite of Kingston upon Thames, a satellite of a satellite - and I was an outcast at school because I was afflicted by the Four Social Horsemen of the Apocalypse: fat, needy, Jewish and top of the class.

Adam would sit in his squat - all the furniture was made of cardboard boxes, decorated with cans of Tennent's, and strange men with beards wafted in and out - and read philosophy. I used to give him blow jobs while thinking about the plot riffs in Jilly Cooper novels. He appeared to dislike me, yet he was always prepared to stick his hand up the ra-ra skirt I'd stolen from Miss Selfridge. I had the impression that he was too drugged to ask me to leave.

I stand outside the cafe, peering at every passerby, thinking, "Is it him?" I remember very well those sad little journeys to Muswell Hill. It always seemed to be raining. I used to get the bus to Richmond and then the train to that exotic, half-imagined destination, north London. We would, for some reason, get into a bath with no water in it, and touch each other. We didn't have sex, because I was too young. The only thing I remember him saying to me was when I turned up with a bunch of flowers for him: "You are the bringer of dead roses." He started to avoid me, and I got the message.

He was so thin when I knew him, and now - as he walks towards me - he's stocky. He has a beautiful face, except he still has no lips. I feel a glow of covetousness; I still want him to want me. (Did he ever really want me?) I half get up to kiss him, but I can't get up further because the table is jammed between us. We sit down. "You look beautiful," he tells me.

"I remember our relationship very well. Lots of oral sex," he says. And I think, "Yuck. Sleazy." He starts to tell me that he runs a software business and he made £3,000 last week. He says he is married to a woman he describes as "unique".

When did we last see each other? He tells me a story I had forgotten. Years later, I had rung him up, and we'd gone to the pub, eaten Thai food and got pissed. At that time, I was a drinking alcoholic. Then we went back to his house to have sex for the first time. Afterwards, as we lay in bed, he said, in the flat drawl of a genuine sadist, "I'm marrying my girlfriend."

I talk to him, listen to him, and I realise that I never knew anything about him. I had no idea who he was. I just took this man and threw all my fantasies on to him; me paint, he wall.

"At that time, I was doing loads of cocaine," he says. "That's why I was so thin. At one point I was down to eight stone." He looks at me, half-closes his eyes and, as if he is seriously wondering, asks why we never got together. Because you showed no interest in me? "Well, I was on a lot of drugs..." And he opens his eyes. "Your party trick was pissing me off, so I would tell you to fuck off," he murmurs. "That's all you were interested in."

Then he says, "I'm not going to tell my wife I'm here." He gives me a shifty, conniving look. Is he...?

I am surprised, but I am always surprised when somebody wants to have sex with me; I usually assume men take off my clothes because they are looking for my wallet. I smirk. You're not coming back to my flat, Adam. "Yes, I am. Let's go."

We walk in the park, then go to a gallery. We are behaving like teenagers, trying to impress each other, and we are almost angry at each other for being so excited. We are on a date, and it is much more fun than it used to be, because we are not in a damp squat infested by cardboard furniture and strange bearded men.

He walks me to the tube and I clutch his shoulders and hug him. He bends his head and gives me a slightly slimy kiss on the mouth. "When can I call you without being a stalker?" he asks. I feel triumphant. My 14-year-old has beaten his 19-year-old to a pulp; somewhere, my Miss Selfridge skirt is cheering.

Another day, another ghost. I met Matthew at school when I was eight and he was 10. I thought he was wonderful because he was the only one of the older boys who talked to me. Then we lost touch until I bumped into him at a station when I was 16. He had become beautiful: half-Irish, half-black, perfectly symmetrical features. "Come to my house tomorrow night," he said.

He lived in a house on Richmond Hill. All I really remember now was that I was desperate to lose my virginity. I must have told him that before adding, coquettishly, that I would never, never have sex with him. "Let's watch TV instead," he said.

We smoked dope, listened to music and drank hot chocolate with cream. Within a few weeks, the virginity was dead. I was the most terrible faker. I went, "Ah, ooh, ah, ooh, ooh." Then he told me, in passing, that he was in love with a boy called Henry. We split up not long after because he was sleeping with half the street: man, woman or postbox.

One night, at a party, I met the boy he loved - Henry. He looked like the hero of High School Musical. I sat and whined about how badly Matthew had treated me. This was only foreplay: I was wooing him. The fact it would hurt Matthew made me want him more.

When I called Matthew to brag that I had shagged Henry, he fell for me. It was a sign of respect. For a year, we spent all our time together. He was very affectionate and he swept me up into a narcissistic fantasy of himself. I was his girlfriend, but he still liked sleeping with other people. We began to have threesomes. I came from the most boring background in the world and this seemed thrilling.

And now he is walking towards me in Euston station. He is 36, but still looks 12. In an Indian restaurant, he tells me he worked as a fundraiser for a major political party and is now a consultant. He is married to a man. So you're gay, I say, chewing a piece of naan bread. "Bisexual," he says. "I kissed a girl 10 years ago."

How did it end between Matthew and me? One night his friend Ian came round for a threesome, and Ian and I sloped off together. The next day, Matthew got his older brother to scream down the phone: "Fuck off, you're so boring!"

"I know I hurt you," he says, "but I was just a kid. If I wasn't gay, I think I would have liked to have made a life with you." I goggle at him, and ask what he didn't like about me. "Your vicious desire to be miserable was very annoying," he says laconically. "And the way you seduced men I wanted to sleep with - that was very, very annoying." He laughs. He has to go to work. We part with a hug. It feels uncomplicated, and warm. I was not to hit real misery until I returned to the heterosexuals - and to the men I knew when I was drinking.

And so on to Jon. I met him in the college bar in Oxford during freshers' week in 1994. He was sitting on his own with a bright red bassoon in his lap, looking angry. So I went back to his room and slept with him. We had sex intermittently for two years. He was very distant. We would lie in bed smoking a post-shag fag and he would say, "I'm going for a run now." And then run away.

Memories come to me in patches of fog. My drinking became alcoholic the week I met Jon, and the story of our relationship is the story of the growing sickness.

I stand outside the station in Cornwall waiting for him. He runs a sheet music shop called Kershaw Music, he told me on the phone. He is married and has a three-year-old daughter called Emily. I feel nervous: he remembers things about me that I do not. He arrives in a big, battered Mercedes and greets me jovially. We go and sit on the beach and stare out to sea.

Jon always said he nearly failed his finals because of me. What did you see in me, Jon? Do you remember I had my first blackout outside your door when you wouldn't let me in? You had to call the porter to remove me. Looking at the ocean, he says, "I thought I would be able to have sex with you. You were available." He doesn't say it callously, just matter-of-factly.

Why did he keep sleeping with me? He sighs. "I thought things would be different. I would think, 'This time Tanya is not going to behave in a crazed manner.' And you always did. After a while, you seemed very calm again, so I would sleep with you again. You were so persistent. You just knocked on the door until I opened it. I think the record was about an hour and a half. You were a bit like the Terminator."

He says it ended because he "finally realised that every time I slept with you, it unleashed a torrent of emotion that couldn't really be stopped by anyone, least of all me." He turns to me, and says, blinking through his glasses, "I am trying to make this sound nonjudgmental, but I think it is tragic that you would quite like to be married but you spend an awful lot of your time going in the other direction. But" - is this a shrug of guilt? - "we had fun, didn't we?"

I am sitting and looking at him, and thinking that I still want him. I want to kiss him. While we are being photographed, I roll on top of him. He takes it well, smiles, and pushes me off. "You'd have to work jolly hard to get me into bed now," he says.

He takes me to the shop to meet Jacqueline, his wife. She is small and slim, with short, brown hair. She seems unfazed about the article, very relaxed, and friendly. He has married the opposite of me. I find I feel no jealousy towards her, although I do feel a little towards his daughter, Emily, who sits in a cardboard box playing with a roll of toilet paper. He is wonderfully tender towards her. He drives me to the station, and waits on the platform to wave goodbye.

The sadness is growing, but I keep going. When I was 23 and drinking a bottle of vodka a day, I started having an affair with Nat, an enormously fat trust-fund boy. He was a kindly Jewish prince, who would purr, "You think you want to go around drinking, but really you want to marry me." I used to get drunk in his kitchen and try to make his lunch, drunkenly stabbing vegetables until he took away the knife. But I was looking for an abuser. I drank more and more and got angrier and angrier. One night I remember driving with him. It was raining over Cricklewood. I said, "Do you love me?" Nat stared at the road and said, "No." I ran out of the car on Mill Lane and never spoke to him again.

Last week, I emailed him and he rang me later that day. I was surprised by what he said. "I think about you all the time. I wanted to ring your mother and ask her how you were so many times, but I was so worried she would have to say, 'Tanya is dead.' "

Would you see me again? "I am desperately nervous about seeing you because I am worried I will fall in love with you again," he says. Nat always was a specialist in yearning. He is not interested in going out with women; he prefers to sit and yearn, and be despised. I don't like this; he is too like me.

He says he won't see me, but he starts ringing two or three times a day, and very late at night, as if the past 10 years never happened. This annoys me - I work now! Why don't you? He whispers into the phone in a way that feels very pornographic. He whispers, "I still masturbate over you. Do you remember the sex?" I try to whisper filth back but my fanny isn't in it.

I stop taking his calls.

I turn instead to the final man on my list. I met Tony at the conference of a minor and quite mad political party in 2004. I went outside and I saw this desiccated thing lying on the pavement, smoking.

Tony looked like no one I have ever seen. He was Rice Krispie-coloured; he had wide-spaced, green eyes, a large mouth and the most awful teeth rotting inside it. He was wearing an opera cloak and a monocle. I sat down next to him. He had a ridiculously posh, drawling voice, like a Disney villain.

He explained he was a writer - thrillers, non-fiction. Before I knew it, I was going to find a cheap hotel with this older man, his outfit flapping in the wind, as if he was a big, needy bat. The next morning we went out for breakfast, then sat in the gallery at the conference and held hands.

He began to ring me every day, sent long, romantic emails, and eventually lured me to his house in the country, a wonky old place that stank of tobacco.

We began to see each other all the time. I bought nice bedding and roast chickens and flowers every Friday night. We watched French movies and read novels. He got up in the morning and wrote poetry, ash from his roll-ups falling on to the carpet in a little pile. All he seemed to eat was meat, like a snake.

At the beginning of our relationship, he told me he went to orgies, and hinted that he wanted me to join him. I knew I couldn't do it: it would send me crashing into bottles of vodka. So I didn't. But he spoke to the depraved part of me.

Now, suddenly, he is standing at the door to my flat, as charming and sweet as ever. "Hello, Mary Poppins," he says. "I am here for a spot of deja spew." He sits down and I immediately just want to touch him. Why? I feel that if you cut him open, you would find maggots. But I still want him. My maggots want to mate with his maggots. My maggots are lonely. So I lay my head in his lap; he pulls my hair, and sighs. "Unfinished business."

He says, "You've put on weight." And within minutes, the black chemistry is back, and I find myself saying, "Move in with me, Tony. Stay." I think I am insane as I say it. He might be the love of my life. I just don't have much of a life.

And then he starts telling me an anecdote and I remember why it ended. "I was at a party last year where I saw a young girl dressed as Miss Muffet get fucked by 16 people."

On Christmas Eve, I arrived after a long train journey and was unpacking when I found a Polaroid of a naked woman on the dresser. She was lying on bedding that I had bought for him. I walked out and never came back.

We hold hands. Then I stroke his face, which still feels very soft, kiss his neck, and chuck him out.

And I weep. I have been meeting younger versions of myself. And I can see a pattern with a clarity that I never did before. It's out of my memory and on a page now: I am drawn to men who can't - or won't - reciprocate my feelings. I am a loser-cruiser. I am Carrie Bradshaw with an axe in her head.

So I call the man I have been referring to as "my boyfriend" for six months. He isn't really my boyfriend, of course; he is like the rest. He is living in Fulham with somebody else, the mother of his infant son. I say, I cannot see you any more. One day you are going to ring me up and tell me your girlfriend is pregnant again, and you will come round and tell me how much money you are spending on nappies. Then you will shag me, and I will hold your head and want to pull it off.

I do not want this, I say. Can I go and at least try to find Mr-Let's-Go-To-Ikea-And-Have-A-Child? Shall I try the Jewish guy in IT with the giant jaw? My mother's friend's cousin who is a solicitor? Perhaps with some more therapy...? He sighs down the phone. "I wish you'd go out with someone normal," he says. "Do you think you can?"