This one’s a long shot, but I’ll throw it out there anyway.
My nephew is about 30 years younger than me. We are both Aspies (undiagnosed until recently).
I always wanted to find a way to connect with him, but we’re both so socially awkward, it never worked until recently. An odd combination of circumstances has allowed us to spend some big chunks of time together. Mostly down time, ships passing in the night, but we have managed to connect to some extent. The proximity, combined with the fact that he’s grown up a bit, and some good things have come of it. I brought him with me to my local Aspie support group, and I even found him his first girlfriend, although that was an accident.
If I had known of all the trouble he was having with his parents, I would have invited him to come and live with me part of the time. I think it would have saved him a lot of trouble.
Are you sure your other relatives dislike you, or is it just an awkward, disconnected thing that no one has really tried to get through? Chances are you are not the only Aspie in the family.
Did you annoy anyone in a particular way and, if so, is it far enough in the past that you can claim a statute of limitations? You can’t blame an 18-year-old for things that happened four years ago.
If you explain as politely as possible (no specific blame or badmouthing) that your whole family needs a break from the stress of living together, you might find that you have a friend after all. It’s worth a shot, and better than another trip to some hospital.