My Big Secret

I was sexually assaulted by my friend during a sleepover when I was 10. He climbed on top of me, pinning me down. He pulled down my pants and his pants then start humping. And then he kissed me. His mom walked in and we never talked about it again. Ive never told anyone that before. Now Im 27 and Ive never been in a relationship or been intimate with anyone. Its incredibly frustrating,embarrassing, and lonely. It happened to me when I was so young. It changed me in ways Im still discovering. It changed me before I knew who I was. Its been hard carrying this secret all my life. Now I feel like so much time has passed that it wont matter if I tell anyone or not. I also feel like I definitely should tell someone. But I dont know how. Or who to tell.