How to stop ruminating on past thoughts and feelings and which ones were real?

So, I know my capacity to get fixated on things. And it's normally something that's relatively remote but, my latest issue is really getting to me and I was wondering if people have any advice. I'm avoiding getting too into specifics, as I don't want this to get reassurance-y but, in essence.. I came to the realisation recently that people who I'd been "friends" (feels like the wrong term now) when I was younger were not very nice people, and normalized a lot of very unpleasant behaviour towards other members of the group. They really normalized it, sold themselves as figures of authority, as older and more responsible and grown-up than others, and looking back, they acted horribly. And coming to this realisation, that I'd been manipulated into just accepting their behaviour has just... broken me. My OCD has latched onto it and I can't stop feeling irreversibly tainted by it. I've talked to others about it, and they've reassured me, told me it's not a big deal and that I hold myself to too high a standard, but none of that sticks. I feel better for a bit, then think 'Maybe when you told them you were skewing it to make yourself look better' or 'Did you leave out a crucial detail'. I keep ruminating over and over, trying to remember exactly how everything played out, trying to figure out if I fed into the behaviour, if I did something bad myself (because y'know, I feel like I was accepting of it at the time, so what does it say about my own values?). I know I need to stop doing all this if I want to improve, but then some part of me keeps saying 'So, you're just going to let yourself off the hook then?' Normally, I can rationalize my own fears to some degree, assure myself something won't happen, but the realness of the situation, and the fact I only came to understand the reality of it because the thought had been bothering me means it feels so much more all-encompassing. I know confessing in itself is a compulsion, but I keep feeling that if I'm not I'm somehow concealing what I 'really am' from others around me, and any positive interactions are me deceiving them in some way. I feel like I can't enjoy anything in life right now, and a good part of me feels I should not enjoy it ever again. If anybody has any advice on it, I'm all ears. Or even hearing if you relate to these feelings, I might appreciate the solidarity at least.

So hard to not engage the thoughts because even though it's from the "past" (i don't even know if im remembering things correctly and it kills me) and i can't change it, I just NEED to prove it to myself that it didn't happen this way. If you'd asked me questions maybe a few months ago, I would have been able to lucidly explain things. Now I just feel like I'm in a constant swarm of thoughts, not knowing if anything is real. If my brain is to be trusted. Wish I could just get hypnosis to forget

Hi all, I’m really grateful for all the support I’ve gotten from people in the last few days. My mental health is at an all time low and I really appreciate the relief people have brought. I had a question about whether an intrusive image of a potentially imagined event can feel just as real as a real memory. I’m doing my best to stop ruminating over an image I have in my head, and have gone so far as requested security footage of myself and have been told both through that and by my friends that nothing bad happened, but the image in my head feels just as real as other memories. I was also drinking the night in question, which makes it harder for me to dismiss the image and makes me feel like I shouldn’t. I was just wondering if imagined images can feel just as real? I’m trying to use tools to ignore the image, and have therapy scheduled for tomorrow, but I feel like I can’t responsibly dismiss the image even with the evidence I’ve gathered if there’s something about a real memory that looks different in the brain and that if so, that suggests my memory is real and I should confess it. I’m really working on stopping reassurance seeking as well, especially now that even after being told that nothing bad happened when the establishment I was at reviewed security footage, my brain is telling me “they’re probably just lying and never reviewed it.” I know I need to just stop ruminating, reassurance seeking, and mentally checking the memory, but I just don’t know if I can/should in case the image is what I should trust more, if that makes sense.