I did something gross as a kid and I hate myself for it

I haven’t been able to stop thinking about what I did and it has actually made me feel so grossed out and disgusted. I had got introduced to p0rn at a really young age. I was in 3rd grade when some people I knew told me what it was, and not that long after in 5th grade I got assaulted twice by some one I thought was my friend. (and during this I was experiencing intense bullying to the point I got taken out of school early.) and again in 6th grade. in 6th grade I was really suicidal I wasn’t in a good headspace and was had a lot of sexual urges like humping my pillow stuff like that. (Which is never and excuse.) but I would let my dog hump me and let him lick me and it happened two different days. a few days later I remembered what I did I was so discussed with my self, I refused to tell anyone what I did and I still live with the guilt . I would cut myself every day to the point I had keloids. I feel horrible it was my childhood dog who died not to long after that and all I could remember is what I did it’s been years now and I can’t get over it and I feel like such a horrible person and I’ve been trying to get rid of my guilt cause I was pretty young (around 11) but I feel like I should have known better.