I'm sorry you're going through this, it's awful. I was a lot like yourself at 18, I didn't socialise, didn't party, never really went anywhere and definitely not alone. You're incredibly brave though, going to college is a big deal for most people, but especially for those who feel this kind of anxiety. You really should give yourself credit for this. You shouldn't hate yourself because its not your fault. You never asked to feel this way. And I would imagine you'd do anything not to feel this way.
When you're out, nobody is laughing at you. People don't stare, we just think they do because of the anxiety. People just look, but they look at everyone around them because that's a normal thing for people to do. You do it too, or you'd not notice that someone else may be looking at you too. We all face embarrassing situations at times, it's just part of life and they very rarely last long. I felt incredibly embarrassed yesterday when I got stuck in a walk through ticket machine at our train station. It just closed on me!! I actually have bruises up my arms where it squeezed so hard. The guy working there just looked at me like I was stupid so I had a go at him lol there were two people (out of a very busy station) who actually did look and laugh, I threw them the filthiest look I could. It was highly embarrassing, but it lasted not even five minutes and guess what? Today I can laugh at myself. Don't worry about what anyone else thinks