I used to have social anxiety really bad. I would literally just curl up in a ball on the desk at college. I felt so trapped by it, couldn't do anything I wanted to.
I got over it by realising that it doesn't really matter that much what other people think. Obviously, in situations like job interviews, it does matter. But in every day life, who cares what someone else thinks of you? I just used to go around thinking "Yeah fuck you" to anyone who looked at me. It sounds harsh, but you have to be strong to get over this extreme self-consciousness.
Just present yourself as best as you can to try and give yourself as much confidence as possible. But after that, don't worry. There will always be people who don't like you, but then they've probably got issues of their own to deal with. Most people will be accepting.
At first you might have to do a lot of acting. I know I did. Pretend to be confident, pretend you have a social life, etc etc. Eventually you'll have pretended for so long and socialised in the mean time, that you will wake up one day and find you don't have to act anymore.
By the way, I suffer from depression too and I understand that it's hard to do anything and feel confident when you're low. However, lack of social contact is probably making your dysthymia worse. A vicious circle.
