The fundamental problem is that autistic people, broadly speaking, don't fit with neurotypical people. A high-functioning autistic person will eventually realize that, and realize just how utterly alone they are in life. They will realize that the people they think of as friends will never think of them as a friend.

First, I'm sorry for what you've been through. But from my personal experience, I know that I have three friends who have autism and/or ADHD. In each case, I did not know this until they told me. If I can't even know who is autistic without them telling me, how can I treat them differently?

Now I understand that it is possible that some behaviours of mine could make my autistic friends uncomfortable, while not affecting my other friends. But if I am doing something like that, it is out of ignorance rather than malice, and I would of course adjust my behaviour if asked to.

So I don't get why you think autistic people 'don't fit with neurotypical people'. I have friends who speak other languages, and autism is also, in a sense, speaking a different 'body language'. With some effort, we should be able to improve communication.