Are you on What I Wish I Knew About University - WIWIKAU on facebook OP? They might be able to give you some good advice on there too.
IMO the non structured format of Freshers, with lots of time with not really anything to do is really not ideal for kids with ASD. Hopefully if he can make it to his lectures and get some structure and routine going, then he might feel a bit better.
I would encourage him (perhaps with you) to consider making a weekly timetable/plan with all the things he needs to do on it, put his lectures on it, put when he's going to go shopping, any clubs he wants to go to even if he's not up to going yet, what time he's going to have lunch and dinner, what time he's going to spend in the library etc. If he can see his week laid out in front of him in black and white, well structured with everything he needs to do on it then he might feel a bit more in control.
Has he made his room into a nice place to be? I know my DS (ASD) would be rubbish at this and literally just have a laptop in there! But if he can make it feel like his space maybe with lego, models, books, magazines, posters, photos or whatever he likes it might make him feel like he belongs there more.
Is he doing comp sci? DS is doing a degree apprenticeship in software engineering and and really enjoying it. I think software engineering is a great job for kids with ASD, DS would be a complete car crash working in a shop, cafe or most other jobs tbh, but software engineering is something he can be successful at. If your DS does decide uni's not working then I know a very pro ASD degree apprenticeship in the SE he could consider applying for next year! (interview questions in advance, OT to organise any adjustments needed). PM me if it does come to that!
Hopefully it won't though and he'll start to find his way. It's such a huge change from home and school for any kid, but for a kid with ASD it's just massive.
Edited to say that i forgot to add that his dad sounds vile and like the last person he needs around him. Why on earth are you still with him OP??