Feeling so guilty over past situation

I have been battling ocd for over a year now and it likes to switch themes. Currently, it’s attacking my relationship with my girlfriend who I’ve been with since I was in high school over 10 years ago. It first began as an intense feeling that I have to leave or break up with her over dumb little things. Then it changed into a lot of guilt for having any thought about another girl. And the worse is feeling this intense guilt for past things I’ve done in the past while in this relationship. We were so young and I was teenager, but I often found myself watching porn, fantasizing about real other people in my life, and getting off to other girls that I may have known. When I was younger I didn’t think it was bad and that it was just a normal teen boy thing, but 10 years later I have so much guilt about it. And yes I’m with the same girl now. We’ve had our ups and downs, but I know I love this girl and I’m ready to propose to her soon. Anyway, these past mistakes I did when I was younger make me feel like a cheater and I can’t stop ruminating about it. I feel like I have to admit every detail and person I’ve ever had a bad thought about. I feel like if I propose to her and don’t tell her everything, that I’m a lair and didn’t give her the full picture. And the other day one of the girls I thought was hot when I was younger, came up in convo and I just went downhill. Now she knows I deal with OCD and she is very supportive, I’ve told her before that I did some bad things, but never all the details. And that’s all my brain keeps telling me to do. I have so much tightness in my chest and just want to be able to breathe again. But everyone says to not admit or it’ll reinforce the cycle, I’m just not sure how everyone else does that. And at the same time, maybe I am a cheater and just simply a bad person. Idk! I never cheated physically or anything like that, but my past mistakes feel like I did. But again I may just be a bad person! Please if anyone has advice or is dealing with similar things, I’d appreciate the help!

I will be straight forward and honest. I have cheated in the past. My last relationship was long term, and I had begged and begged for him to change and in the end he never did. I don’t know why I cheated. And I’m not going to make excuses for myself for why I did. I messed up. The cheating was online, it was never in person. But now, I’m in a new relationship. And he’s everything I have ever wanted in a boyfriend, husband, and best friend. I want this man to be with me the rest of our lives, and I want to see him help raise our future children. But I can’t help but feel such immense guilt, because although I have never cheated on him, his ex had cheated on him. And I truly don’t understand how or why she would…but that’s not my place to comment on. Such a big part of me wants to tell him, and tell him that that’s not me anymore, and I know that we will communicate healthily and openly, unlike my last relationship, which he never wanted to. Not only this, my brain just won’t. stop. thinking…about how I had cheated. I regret doing what I had done, I don’t WANT to cheat anymore, or ever again. Especially with the love of my life I have now. But I’m scared of what do I do if I have a compulsion, or anything revolving around cheating. I want to tell him about it, but I know I shouldn’t, and can’t really tell him as it’s complicated, and I know I would only make things worse. I feel like such a terrible person, and girlfriend, for what I have done and what I’m worried about ‘if I do’, even though I don’t want to. I want to be better, I want to grow. Any advice please would be amazing.

okay so, i had this friend i met in the 8th grade when i was 13 when we became friends and my nickname for her was “red” and i had a crush on this friend before we became friends and once we became friends the crush faded away and i just grew a close platonic friendship with her and no longer has any crush or attraction or romantic interest in her. then i got a girlfriend named lisa in the 8th grade also and we were all friends and hung out but that summer going into highschool lisa broke up with me, we dated only for 2 months so you know it wasnt a big deal. and my friend “red” she and my other friend lana we are a trio and they helped me move on from that. then i started 9th grade (my freshman year of highschool) and i went into this year thinking i was gonna stay best friends with this trio but we ended up splitting paths but me and my friend “red” always had a more special bond in the trio we were like the duo because we trauma bonded and dealt with mental health problems. and in the end of my first semester i fell in love with this girl named riley (who became my 3 year serious relationship) and i love this girl so much i met her when i was 15 and she was 14, me and riley (who is my current partner) were very toxic during freshman sophomore and junior year. she was very insecure over my ex from the 8th grade who i didnt care about because she was my first girlfriend. and she was also very insecure over my friend “red” because she was my best friend during the time i was with my ex and she reminds her of my ex for some reason. i still wanted to be friends with “red” at the time and we would get into numerous fights about that. she would control me and who i was friends with and said i couldnt be friends with her and i felt so awful and defeated bc i had a close bond with this friend. she then gave me an ultimatum of either her or my former best friend and i chose my partner obviously but she was so in her head i think that she still broke up with me for like 3 days and that day she broke up with me i had to go home with her since she was my ride home and i was broken and she was obviously angry and i was crying while we were walking out of school and then she stormed off without me all upset and my other guy friend and his girlfriend saw me and went up to me to comfort me and asked what was wrong and i told them she broke up with me and then my partner yells my name very upset from across the street comes back and grabs my arm aggressively and drags me past everyone very aggressively and angry while telling me to stop crying because her mom is going to be upset and ask questions and i felt so bad. we got into the car and i had to try my best not to cry and my partner who was visibly upset a few seconds ago just completely smiled at her mom and asked how her day was with such a happy tone of voice and i was completely in shock. hours later since we were broken up i texted my former friend “red” (the one who my partner broke up with me over) and told her i needed emotional support that reyna had dumped me and i needed a friend. and she came over and talked to me. that was all nothing romantic. and then 2 days later my partner says we are back together and i was happy but felt guilty because i hung out with my friend who she dumped me over. Now years later im still with this partner after many splits but we are finally healthy and healing and shes been super supportive and there for me and loving during my recent journey discovering my ocd. i have been confessing over and over many past mistakes or things i thought were mistakes. i last confessed something on monday and ive been feeling better and relieved after confessing up until yesterday when i remembered a past mistake (which was what i just shared) and now i cant stop ruminating on it and feeling guilty and feel the need to confess this to my partner but i learned that confessing is my ocd compulsion and if i give into it ill be feeding my ocd and not breaking the cycle. but im also feeling conflicted on if i should genuinely let her know and confess because i feel what i did that time was wrong but i dont want to give into my ocd but also what if i basically cheated on my partner by doing that and if i tell her that i did what i did even tho i didnt cheat but i told her i never liked this person even tho i had a crush on the former friend and tried to get my partner to let me keep this friendship because its not like i like her romantically which is true i dont but i used to. so i feel like i betrayed her even especially by hanging out with her so now i dont know if i should tell her or if its my ocd and i dont have to share absolutely everything especially if its in the past. i dont want to lose my partner and im scared if i keep confessing it will ruin our relationship and drive her away but it will also make me lose myself and my own privacy and also feed my ocd and compulsions but im scared if i dont confess ill never stop thinking about it and i will feel like im lying to my partner and like i cheated and i wont be able to enjoy the good moments and the present because im stuck on my past “mistakes” and now im scared ill have the end my relationship to feel better but that will hurt me more but im scared if i stay im just going to try to avoid my partner in fear ill confess or feel the urge to confess every time we speak. i dont know what to do im completely lost this is the hardest thing ive ever dealt with and i have a lot ive dealt with in my life already. im barely 17 i havent had a year of a break