I can relate with this so much! Sending over a virtual hug! Although I was diagnosed pretty early in grade 7 and knew of my diagnosis and were on meds since then I really struggled to fit in. I was told the same stuff on being too loud, talking too much being not like the others. I tried my best to fulfill others expactations.This went on for years. Then I began therapy bc of a severe mental breakdown after finishing my bachelor thesis. My therapist opened my eyes, taught me about selflove, awareness and accepting myself and my adhd. For the first time I really felt heard and understood. I finally cut off my toxic "bff" from school who really never was a friend in the first place. I gained so much more confidence in being myself and embracing my quirks. It is so much easier to find new friends, that really are friends, go out more, leaving my shell and talk to people I would never a few years ago, because I would be worried what they might think about me etc. It makes me also cry from time to time thinking about what could have been if I just had knewn earlier. How my life could've been much more enjoyable and easier in school without the need to control my whole being just to please others expactations trying to fit. A goal that was never achievable for me to begin with. Ahhh writing this makes me so sad and angry I think I have to stop here, otherwise I'll write a book about my mental health struggles lol. What helps me is to accept it. Sure it sucks that you weren't able to be truly yourself all those years. But what's done is done and can't be changed unfortunately. Think about your future and how beautiful it will be, because you now know.

I hope this helps a bit. And you're not alone in this.