Morality OCD and high school

So I have cheated on tests and exams before, and I just now have started feeling guilty about it because of my OCD flare ups among everything else in my life. I also have really bad relationship ocd that I may cheat or may have cheated in the past (I didn’t) and so having these thoughts that I cheat in school makes me feel like a really bad person. I didn’t feel bad about it until now, because I know that it’s wrong. I still can’t shake the feeling of guilt and I feel like I should confess to my professors.

17f I have a lot of events, but my main and my worst one which is absolutely fucking diabolical was done when I was 14 and repeated when I was 16. Everytime I post something about real event ocd here people are like you are probably didn't do anything that bad, and when they hear what I did they are like yeah that's bad. Someone even asked me if I'm autistic cause "it's crazy how you didn't realize that the thing ypu were doing was wrong at this age." And I kinda agree, like it's fucked up It's just that my event is bad. Doesn't mean I don't have real event ocd. You can have a reocd over the event that was bad, it doesn't mean the event wasn't that bad or you don't have recod. It's just people always expect it to be something innocent and it's not Even a healthy person would feel guilty over it, it's just that I had ocd my whole life and it's making the guilt absolutely destructive, like to the point when I sometimes have a hard time breathing when I think about it, I lost more than a year of life to it, almost checked myself out couple of times if I wasn't so scared of pain/failure, the event haunts me in my dreams, it's in my head 24/7 and I will never able to forgive myself. That ocd. But the event itself was bad. So maybe i deserve it.

I think I know what honestly is what caused my OCD. I’ve never told anyone this but I have to if I want help. When I was either 10 or 11, I think 10 I was at my family’s thanksgiving dinner. Around this time I discovered porn and got addicted. I would watch porn and read erotica. Because of this I guess I wanted to experiment. I feel absolutely horrible just thinking about this but I was playing around with my little cousin, he was around 7 I think and I remember we were playing chase or hide and seek, and I grabbed him and hugged him (something I never done before), and got a boner. I did this for pleasure. That’s all I did that was sexual but I feel so horrible. I try to give myself grace as I was only 10 and didn’t know the consequences of something so disgusting. I keep thinking “what if I went farther and hurt him?”. I talk to him sometimes and he seems comfortable with me and I think he doesn’t even remember this ever happened and just thought I hugged him for some reason all those years ago. I am NOT attracted to him at all but I think this incident and remembering it when I was 14 has caused my OCD such as POCD for all these years. I am 18 now but I feel absolutely horrible. And now it’s even worse because I have been invited to his 15th birthday party in Mexico. I’m traveling all the way to another country just to be near him! Obviously I know I won’t touch him or be innopropriate with him. But what if he has felt uncomfortable with me all this time? He seems fine with me and not uncomfortable around me but still. If I feel as if I go to this trip, I am a horrible person. I don’t know what to do. Am I a horrible person for what I did and continuing to be around him? I remember reading Reddit and Quora stories of similar people who felt horrible and people told them to not feel bad as they were only children and they learned and now know that was wrong and that to not tell anyone as it could only make things extremely awkward.Please help. I know COCSA is a very serious topic that harms people and I feel like a horrible perpetrator now.