bitter after diagnosis

have no idea why, but this got flagged as spam so i'm retyping it.

i'm corvus - i'm 18, and i was diagnosed as autistic a week ago.
i've known i was autistic since i was around 14 years old, but my road to being assessed was blocked numerous times by my highschool, and my parent.

when i was told by the psychiatrist who had been interviewing me that he was going to diagnose me; i was relieved, at first. finally, i felt heard for the first time in my life. i wasn't faking this - i am autistic, despite the people around me denying so.

however, this conclusion has made me begin to reflect - and this reflection has brought back some very unpleasant memories and feelings, amplified with the knowledge i am autistic.
the way my parent, my past teachers, and even cahms had acted towards me...of course, even before this week i knew what i had went through was horrible, but now it's in an even worse light in my mind. i was never taken seriously, despite my very obvious distress and struggling everyday, which turned into severe mental health issues. i felt like i was a burden to everybody, and now i know that it wasn't even my fault. my school never had the ability to accommodate an autistic person, that was the truth.

and with that, comes intense bitterness over what i had went through. i often feel like i mourn the person i could've been if i wasn't treated like this; who i could've been if i was given the proper support i needed back then.