Sorry to hear this, @SqueezyCheesyPeasy . I have been in this position with DS3 (and we thought he was the NT one!)
Ds3 started uni in 2020 which was not a great time to start as all teaching was online.
I think, any other year, he'd have been fine. The first year he got on great with his flatmates, all a great laugh and he loved it. But after the first year, his flat mates packed their courses in or went home.
That left him with no one to share with so he got a room in a private uni accomodation. The last available room next to the kitchen and all girls.
Because the girls went about as a big group and had boyfriends back, that kitchen got very rowdy. There was actually quite a bit of damage done. And DS3 showed the exact same behaviour as your lad.
He had self diagnosed with social anxiety and, pretty soon, he could not go into the kitchen.
His course remained largely online (it was a software engineering degree)
However, he found himself an online girlfriend in America and that saw him through 2 years. He spent 2 fabulous summers in America and had no trouble at all making a 3 plane journey by himself there and back, he was fine over there and managed a job over there no problem. He returned to his flat term times but was in constant online chat with the gf.
However, Christmas 2022, there was more partying and damage in the kitchen and a meeting was called. DS obvs said he had not taken part in it and at that point he asked to move back home.
As lectures were still largely online, we agreed to this. He completed his course from home (got a first!) Relationship with gf broke up.
He got his confidence back working in a charity shop first, then got paid shop work and he is still at home, working away at his CV but also out in his shop job every day and he seems happy and fine.
Im sure he would go back to how he was though if in that situation again.
Moving into the studio flat might be the way forward - especially as he is coping otherwise. I totally understand your worry. I have a friend whose dd is in this same situation. It seems to be a common thing these days.