This may sound harsh. For that, I'm sorry...
You keep saying "I should have..." You cannot unfuck a situation after the fact. Sitting around wallowing in the shoulds of the past are not doing anything positive for you. You're merely creating your anxiety.
You're very very young. That's both a good and a troublesome thing. Good because this happened young. You have your entire life ahead of you. Troublesome, because you're young and haven't yet developed the life skills and emotional maturity to know how exactly to cope with what you're feeling. Neither of these things are bad. My brother, I promise you'll get through this.
This book changed not only my outlook, but also my life, for the better. Maybe it can help you.
F**k It: The Ultimate Spiritual Way https://www.amazon.com/dp/B07K3VTLP8/ref=cm_sw_r_apan_glt_ZM30V0JC4MVS2S4H2ZEX
Last, look into mindfulness practice. I think it will be so helpful.
I know it hurts buddy. However, I promise, it will get better.
(((Hugs)))
What initially looks and sounds like a joke is revealed over a relatively short count of pages to be the ultimate side road away from fear, anger, and sadness. I still have my issues of course as anyone does, but it's a lot easier for me to let a lot of things go because of this book.
When you say cancelled, what exactly do you mean? Were you cancelled for something you actually did, or was it generally a nebulous situation where you were essentially accused of 'mind crimes'?
And I find it hard to believe that any run of the mill schmuck could actually have a stranglehold over a 'scene' of an entire city, unless the city is actually a small town or the scene consists of less than 50 people. This comes off as just being friend drama with a huge backlash in some pseudo-influencer group. I don't mean to diminish it's effect, but I think that could be an aspect of why it's sticking with you. The reality is it was probably transient drama around a bunch of dramatic people with no real substance behind why you got so much shit.
I think you're already kind of accepting that it probably wasn't as serious as it originally seemed back then (could be maturity), what you should try to work on is the nagging feeling that it is somehow not in your past. Unless this was something where you actually committed a crime which shows up in a google search, I don't think you should continue worrying about it.
To be completely frank, I think this is a perfect example of why the whole 'canceled' fad was and to some extent still is such a cancer within our culture. It's all about harassing people, rarely looks at if they did something clearly wrong and can have a permanent damaging effect even if the claims were unfounded while giving the person no way to really correct themselves.
Maybe you should just be happy you're no longer interacting with a bunch of people who are so clearly toxic. I had a similar situation when I was very younger (teenager) where it was pretty much just an influential person in my social circle decided they were pissed off at me and started poisoning people against me whenever I wasn't in the room to the point that I just began hanging out with new people. Maybe try reading certain works like 'Fuck It' (honestly this is the best getting_over_it book I've read) or maybe approach it from a religious viewpoint of a perspective like Buddhism's views on attachment to the ego (whatever meshes with your beliefs/style).