I go first to our shelter where the girls we've rescued live. They can be hard to manage — they want to break everything — but I take them in my arms and we understand each other. In Cambodia, parents sell their children when they're five or six for as little as £60. Girls prostitute themselves for less than £1.

It's what I've been through that gives me the strength to fight back. I don't know who my parents are. As a child I remember being cold all the time. I was abandoned and raped when I was 12. Two years later I was sold off and forced to marry. My husband would get drunk, he beat me and raped me, he'd fire bullets which passed just by my head or my feet. I took the gun and shot him in the foot. I was 15. I didn't want to kill him, just hurt him as he had hurt me. I'm more of a Buddhist now, and I try to be reasonable. But when I see rapists I see red. I'm not perfect.

My husband sold me to a brothel. I had to accept five or six clients a day. Once a client called me and another girl; he said he was with just one other man. In fact, there were 20 of them; they treated us so badly I wanted revenge. I wanted to kill the man who called us. Then I thought his family would suffer, so I left him alone.

People laugh about prostitution being the oldest job in the world, but I've seen so many awful things. Girls are chained up and beaten with electric cables; one had a nail driven into her skull for trying to escape. Another, Thomdi, was sold to a brothel when she was nine. When I saw her in the street she was 17 and sick with Aids and TB. She had lots of abscesses and the people at the hospital insulted her and refused to take her in. So I took her home and washed her. She started to get better. Then I had to go abroad. She told me she would die without me, but I had to go. I was buying presents for her when I got the call that she had died. I still feel guilty about her death.

Around mid-morning I go to the offices. I'm back on the computer and I check on the girls' health, and how they are doing at their jobs. The association has a staff of 134, including doctors, psychologists and teachers. Since we set it up eight years ago, we've saved over 3,000 girls and found them normal work.

Our job is dangerous. Once this man who ran a brothel put a gun to my temple; he was angry that I'd talked to his girls. He told me I was a bitch, that he was going to kill me. I talked to him — I knew he wouldn't kill me. People with a gun kill you or they don't — they don't pretend. After, I got him arrested. I don't have bodyguards — I want to be free.

For me, meeting a politician or a donor is much worse than having a gun pointed at me. I didn't go to school, I don't find it easy to talk and behave properly with a bureaucrat. I have to say the truth, which hurts, but if you don't tell the truth, nothing changes.

I'm usually too busy to have lunch, but if I eat something it'll be boiled white rice and fried vegetables. Around 2pm, we hold meetings, we talk about the girls who are ill or have difficulty finding a place in society. And there are always e-mails — I get 200 to 300 a day.

The hardest thing for me to cope with is corruption. I filmed a police raid on a brothel — there was cocaine there. But then in the courts the judge said it wasn't cocaine, it was flour. We once caught a German paedophile on camera, but the courts let him off with a £4,000 fine. He went back to his country. Is that fair?

Last December we rescued 89 women and children in a police raid on a big hotel. But the pimps went to our shelter and grabbed them back. The next day they threatened to come back with grenades. I phoned everyone I could for help, but I was told I'd gone too far — I had bothered powerful people. I make a point of going to see the criminals who threaten me. I have to show them I'm not afraid by talking to them.

I get desperate at times; I tried to commit suicide two or three times. When things are overwhelming, I try to be alone somewhere dark and quiet. I can be bad company; everything makes me angry. I'm separated from my husband and I don't think I'll have another relationship. I'm not young any more; I don't want to make a man unhappy.

One or two nights a week I meet girls in brothels or on the streets. I talk to them and tell them what we could do for them. But usually I go home at 7 to cook for my children. They are in bed by 10, then it's quiet and I go back to my e-mails.

I can be at the computer until 2am.

I don't sleep well. Especially when I have to meet journalists and they ask me about my past. When I close my eyes I feel raped and dirty. I'm very weak. At night when I don't sleep, I think that right at that moment many children are being raped. The pills I used to take don't work any more. But I can get by with two or three hours' sleep. I don't know what being happy means. But I like seeing the girls smile. That makes me feel good."

The Road to Innocence, by Somaly Mam, will be published by Virago next year. E-mail: somaly.mam@afesip.org