Was this sexual abuse?

Ok so this is a long ass story but please read it all because I’m really confused about it and I need help. So my cousin (not really my cousin by blood. It was my moms step moms grandson that she adopted. Complicated I know. But basically we’re just related by marriage) is two years older than me. The first time something sexual happened between us was when I was about three or four and he was five or six. I was at his house and my mom came to pick me up but before I left the room we were in he pulled down his pants and told me to “kiss it goodbye” so I did. I don’t remember much happening after that until he was maybe twelve or thirteen and I was in his sisters room and he came in and we were playing a game and he turned out the lights but when his sister turned them back on his pants were down and his dick was out. He didn’t try to cover himself at all. He actually just stood there and pointed out his public hair. Shortly after there was a game that was started with all my cousins of “extreme truth or dare” which was basically just a bunch of sexual dares. At one point I got the dare that I had to either get naked and lay on top of my older cousin or he had to do it. If I said no then I had to “toss someone’s salad.” He had a boner and I could fee it on me even though I got to be under the blankets and him on top. I think at this point in my life all the sexual stuff between us had become so normalized that I didn’t think it was too wrong. But one night my sister and I were spending the night in my girl cousins room but it was really hot in there so we went to her brothers room. After they were asleep asked me if I wanted to play truth or dare so I did. He had me show him my boobs and he touched them and sucked them and had me touch his penis. After this had happened for a few minutes I got this awful guilty feeling and went back to the other room to sleep. That night my grandma heard us go over to his room so the next day she made my mom come pick me up and I sobbed the whole way home. I was 11 or 12. That was about the time I got really depressed and suicidal. I thought that if anybody found out what I had done then no one would love me and I tried to kill myself because of it. It wasn’t until recently that I found out that child on child sexual abuse was a thing but I’m still confused and feel guilty because I liked how it felt when he was touching me. But I also read that being coerced and having it turned into a game makes it count as abuse but I’m still not sure. I feel bad that I hope it is so that I can stop feeling so guilty about it. I’m 17 now and I told my mom about six months ago and she was really upset at first and wanted to kill him but after a couple days she came to the conclusion that it was just child curiosity and I’ve just accepted that because talking about it brings up a lot of suppressed feelings. I’ve asked to see a counselor multiple times (I struggle with periodic depression and bad anxiety) and she said I can but has never made an appointment. I just need some input because I’m still confused. I still have to see him sometimes but it makes me horribly uncomfortable and I hate being around him. What really bothers me is that the night this happened the girls were not allowed to go into my boy cousins room (which is why I was sent home). A while later I asked my girl cousin why that was and she said that my grandma thought me and my boy cousin were having sex. I was in sixth grade. Hell, maybe fifth grade I don’t remember. I’ve spent so long trying to block it out. She knew something was going on and she never said anything. She heard us go over to his room and she stayed in bed. She never tried to stop it