How to stop rumination and let go?
So here's the issue: my mind constantly thinks of my past mistakes/embarrassing things I've said and done when I was in my teens and younger. I could rationalize that my mistakes are due to ignorance and some may argue it isn't even "that bad," but I still can't help but feel immense guilt over it---like, I cannot forgive myself for not knowing better and committing mistakes. The saddest thing about all of this is that I give so much grace to people who have done wrong and perceive people in a grey, nuanced way. But when it comes to myself, it's in black and white, that I couldn't afford to be human and fuck up, basically. I have this intense need to be morally upright at all times, and if I don't know any better, I'm automatically a bad person. I know that sounds too intense, but that is how my mind works every day.
An extension of this rumination is worrying that people will expose my mistakes, cringey moments, or personal details about me one day. This has caused me to delete messages and several accounts I own, but that still hasn't stopped me from worrying because what if someone out there have stored screenshots of things I've posted and said in group chats. I could convince myself that people don't really care, have long since forgotten some things I said or posted that might've potentially been embarrassing or offensive, people care about their own problems to even do something to that degree, and that I've never had bad blood with anyone for them to come for me like that. But that hasn't stopped me from overthinking such scenarios. Maybe seeing celebrities and public figures in general get cancelled all the time for stupid things they have said or done in the internet years ago is getting to me. I've worked so hard to unlearn a lot of toxic things I've picked up in my childhood by continuously educating myself and unpacking the reasons as to what led me to do certain things etc. But what if that is not enough and the mistakes I've made undermines everything I worked hard to fix and change?
Additionally, I would also get blurry memories and wonder if I actually did something wrong in those situations then try to patch up bits and pieces of memories I have to maybe fill in the gaps. I'm not even sure if these memories I have are even real or if it's just another way for my screwed brain to crucify myself even more.
I have distanced/silently cut ties with a lot of friends I made during elementary school up to high school because the things they believe in or have said do not align with my morals, not necessarily because I think they are terrible people (again, I don't see people in that black and white way), but because I fear that if other people see that I still converse with them despite their problematic views that I am complicit, thus making me a walking contradiction who claims to have certain sets or morals but doesn't abide by them.
I do think this is some mental health related issue I need to unpack. I have some guesses of what I could have, then again I'm not going to self-diagnose. I cannot afford therapy or going to a psychologist right now, which is why I wanna ask what I can do to change how my brain functions because I'm honestly tired of living in constant fear and self-hatred--making up a problem that does not exist yet or will never be. I also wanna know how I can stop worrying about what other people think of me... thank you.