Struggling to be Myself as an Autistic Person

I am autistic. I feel like I am supposed to have stims, and I clearly remember repeating phrases I found interesting over and over as a child and doing certain things with my hands which others perceived as "weird" or "atypical". Whenever I try to be myself, people assume I am stupid, drunk, or high on something. People tell me I talk too loudly and have often refused to listen to well reasoned arguments for things I am passionate about because I am too loud or they "don't want to talk about controversial subjects". This has led to years of being mistreated and not heard, and now I am severely depressed and anxious without my medication. I don't deny the severity of depression, especially my own, at all. I have been there... and I am referring to a particular general class of actions which I would rather not specify due to how it triggers intense emotionality in myself and potentially others. These are actions which often carry the consequence of psychiatric hospitalization. I am deeply resentful of how I have been treated and continue to be treated by some people. This has built up to be a significant source of anger for me. I am very principled and believe in physical violence as ONLY a last resort self-defense when you have zero options for escape. Yet, people assume I will become violent when I get angry, because when I get angry, it is more of a meltdown than violent intent. I only get angry when I perceive that someone absolutely refuses to listen to me. This has led to people falsely assuming danger and calling the police for example. Invariably, the police see that I am not a threat other than maybe a bit loud, but they are ill-equipped to truly help. Nobody, not even my parents, seems to understand how I feel or think. They refuse to understand, apparently. I am so sick of feeling afraid to be myself. I have no real ability to mask. People notice that I don't look at them, that I'm "weird", and have a tendency to discuss things at great length and zero fear of controversial topics. So I usually stay quiet and avoid everyone and everything, which not only doesn't solve my problems, but can make things worse. I suppose I am asking for help finding myself again and dealing with situations and people that frustrate me.