Child sexual experimentation

I have recently remembered something I did as a child, when I was about 11/ 12, I remembered this a few months ago but I’ve remembered a few more things from what had happened, I was about 12 and I had a cousin about 5 and I remember only once when I was in a room with just him and me, he came next to me and I think I pulled him a little closer to me I then wanted to try out something, a little bit of domination I think.... I pushed him on the bed and started to dry hump him, his clothes where on and so where mine, he didn’t seem fazed by it and I stopped pretty quickly, now I’m 16 and I feel disgusted by what I done, I wasn’t trying to hurt him and I would never do that now, I feel so bad and didn’t really know what I was doing, I had watched porn at a young age as a friend of mine showed me in year 7 and I remember I had seen it before hand, I also walked in on my parents a few times before. I feel so terrible for what I have done and I would never do something like this again. I’m sitting here thinking to myself, did I sexual abuse my own cousin? And it’s horrible to think that I might of done, what would police think of this? I done this once and would never do his again. Please someone help.