I just need to vent everything I've held in for so long.

I've been holding onto so many secrets but it's been killing me.

First I remember when I was 10 my mom dropped me off at my grandmas house and it was just my grandma and my cousin (he was 16) who was in the basement playing video games and I decided to go downstairs because I wanted to play and he said let's play hide and go seek and of course I agreed. So I start hiding and after a couple minutes he comes looking for me, he found me not to long after counting and when he did, he grabbed my pants and took it off, and touched me down there and I told him to stop and he didn't. He didn't stop until i somehow started kicking. I remember running upstairs to my grandma petrified that I would happen again, I never told anyone about this, because when I think about it I feel dirty and ashamed, why did he think it was okay to touch me like that? What did I do that made him think it was alright? I feel as though it's my fault, maybe if I didn't ask to play none of this would of happened.