Dropping out is the nuclear option. I understand how you are feeling and why (those people sound awful), but it really would be a BIG decision this late in the day.
I'm not sure what to advise you. As part of my work I deal with disability support and I have some particular expertise with autistic people - I am aghast at the lack of support that you are (not!) getting from the institution. Normally I'd say you ought to kick up a stink about this and ask for some accommodations, but from what you've said, I don't know what good it would do.
I'd probably still be minded to try, perhaps with the support of your student union if possible. I think you should give yourself a fighting chance before hitting the eject button on the course, but that's very easy for me to say, less easy for you to do.