I spent three years at Uni without making a single friend. Without even speaking for months at a time.
Above all, I wish I'd admitted I had a problem and then
done something. Seen the counselor, explored CBT etc. That way I could have begun to question the way I think about things and the way I act.
I might have begun to wonder why people aren't speaking to me: could it mostly be because I'm actually avoiding them when the opportunity arises? Rather than them avoiding me? Am I trying not to make eye contact? Not taking the initiative to voice an opinion, instead waiting for a direct question?
Do I really dislike partying? Or is it just because I am afraid of doing something so completely social due to my SA?
Is there really nothing I have in common with others? What about being a new student at the same university as someone? Is that enough? How much do I have to have in common with someone before I can get on with them? Does it make sense to ask that question? And how do I know if I have anything in common with them if I have never spoken to them?
Whatever you do, don't just sit in your room brooding for three years. It's not that great, trust me, and you'll definitely regret it.
It's not easy, not as easy as avoiding everyone, but you really do need to push yourself to get things to change. It'll be slow, but you will see progress.