Autism is such a wide spectrum. Many I've met were very gentle and kind so every individual is unique. Sometimes people believe that Autism = Violence because they met a person or two who were. I don't doubt there are some out there, just as much as non-autistic people can be violent, too.

The behaviours you're describing does not sound "Autism" to me. There are other things going on with him. Many do have specific obsessions but I believe it stems from what they've learned from their environment so I'd wonder what happened to him when he was younger that made him turn out this way. Gang member dad? Unsupportive mom? Bingo. It's not the Autism in him. It's 100% the parents. He needed intervention a long time ago. Now he's developed patterns of behaviours which can be very difficult to break in people with autism.

I would contact social services and ask for support and guidance. I would also end this relationship. I really feel for him. I really feel for you, too.

I think your partner is using you which is why she came on so strong in the beginning. She was desperate. She is of no help, from the sounds of it, so telling her to move out won't make your health condition harder to manage.. it may make it easier because stress really eats at a weak system.

I'm sorry you're going through this. It's not worth it.