Hey,
Not going to pretend that I have any particular advice for dealing with what you're going through, as it sounds kind of similar to things that I've yet to cope with and still struggle with in my own life, but on the offchance it might make you feel a tiny bit better to know that you're not alone...
I started uni 3 years ago. I had a lot of trouble talking to people. I didn't go out. I didn't socialise. I just stayed in my room for the best part of six months! My housemates were nice, but I never really bonded with them at all, as on the few occasions when we went out together (fresher's week) I was too anxious to get to know them properly. I'm pretty sure they thought I was strange. It got to the stage where I would avoid cooking meals just so I wouldn't have to meet them in the kitchen, and endure the awkward feeling I got. Every time I left my room I would feel incredibly anxious.
I feel like I kind of know what you mean about wanting to change but just not being able to. I remember being caught up in a situation like that, its very hard to look beyond it, or think that you can really be any different. It's easy to look back and think 'I could have done that' afterwards, but when you're actually there its different, and you just feel kind of powerless.
Eventually it got to the stage where I felt I just couldn't go on anymore, and I decided to drop out. Luckily my family were very supportive, but I kind of regret not dealing with my issues at the time, as they've only got deeper since.
I'm now (also) 22, and it still feels like I have no life, despite attempts I make every now and then to break out of my rut and meet people. Never had sex or a serious relationship, and I know it feels embarassing and is just another thing to get anxious about. Plus, I'm a bloke (not sure but think that's 'sposed to be more embarrassing?) I'm also living at home (how loserish is that?), and worrying about applying to return to uni again next year.
Like I said, I haven't got any proper advice to give you. Hopefully what you're going through isn't as extreme and it will get easier as time goes on (think everyone feels pretty anxious at start of uni.) If it doesn't...well, like Star said, there's counselling. You definitely want to get someone on your side to support you, as it sucks to feel alone, and if your family don't understand then someone else to give you perspective and support might help. There's obviously a whole range of therapies and treatments to deal with social anxiety, if that's the problem - CBT, EMDR etc - which you could ask a counsellor about or read up on. But obviously you have to have the motivation to go through with them. I'm currently looking into something called 'autogenic training', which is supposed to help calm anxiety through training the body with breathing techniques.
I suppose one short term bit of advice I might give you, which kind of works for me sometimes, is to try shifting your focus away from yourself and onto your environment. Instead of allowing your anxieties and worries to dominate your thinking, move your awareness onto the world around you. Don't focus on what someone could be thinking about you, or how you look to them. Only focus on what's actually happening at the time - what they're saying, sounds in the background, the way the light shines through the window. It can be kind of relaxing just to lose yourself around other people, and just be. Anyway, that probably sounds pretty garbled, but you could try it. Maybe make a point of just going out, sitting down around other people, and relaxing, losing yourself in the world around you. If people talk to you, focus on what they're saying, not on your thoughts, and just respond however you feel like. Sometimes its good just to be around people without any pressure or expectation. Not sure if any of that made any sense but if it didn't just ignore it, I'm new here.
Hope your nightmare ends soon