The Pulitzer prize-winning novelist Junot Díaz has revealed in an essay in the New Yorker that he was raped by “a grownup that [he] truly trusted” when he was eight years old.

The Dominican American author, who has explored the subject of sexual abuse in his fiction, has not previously spoken publicly about his own experience. But in an essay titled The Silence, Díaz addresses a reader who approached him years earlier at a book signing and asked if he had been sexually abused himself. At the time, Díaz did not reply.

“I’m still afraid – my fear like continents and the ocean between – but I’m going to speak anyway,” he writes. “Yes, it happened to me. I was raped when I was eight years old. By a grownup that I truly trusted. After he raped me, he told me I had to return the next day or I would be ‘in trouble’. And because I was terrified, and confused, I went back the next day and was raped again. I never told anyone what happened, but today I’m telling you. And anyone else who cares to listen.”

Díaz, who won the Pulitzer for his debut novel The Brief Wondrous Life of Oscar Wao, writes of how “that shit cracked the planet of me in half, threw me completely out of orbit, into the lightless regions of space where life is not possible. I can say, truly, que casi me destruyó.”

He didn’t tell his family, and found his childhood scarred by fits of depression and rage. “While other kids were exploring crushes and first love, I was dealing with intrusive memories of my rape that were so excruciating I had to slam my head against a wall,” he writes.

At college he reinvented himself, but he continued to keep the sexual abuse a secret – although he touched on it in his fiction: “Somehow I was still writing – about a young Dominican man who, unlike me, had been only a little molested. Someone who couldn’t stay in any relationship because he was too much of a player. Crafting my perfect cover story, in effect.”

Díaz writes of reaching “rock bottom” after a woman he loved discovered he had been cheating on her repeatedly, so he went to therapy. He has since told his friends, “even the toughest of my boys”, about the abuse; previously, he had been “afraid that the rape had ‘ruined’ me; afraid that I would be ‘found out’; afraid afraid afraid. ‘Real’ Dominican men, after all, aren’t raped.”

“I had to lose almost everything and then some. And then some. Before I finally put out my hand,” he writes, to his unnamed reader. “I think of all the years and all the life I lost to the hiding and to the fear and to the pain. The mask got more of me than I ever did. But mostly I think about what it felt like to say the words – to my therapist, all those years ago; to tell my partner, my friends, that I’d been raped. And what it feels like to say the words here, where the whole world – and maybe you – might hear.”

• In the UK the Samaritans can be contacted on 116 123. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255.