Was I wrong to yell at my suicidal mother - help?

I just started college today - my social anxiety is so bad and I'm once again considering dropping out. The only person I spent time with as a child was my twin sister. Starting school came as a huge shock to us and we've hated it since day 1. We're 23 now and don't have any friends. We're both depressed and it feels like it's us against the world. I got into an argument with my parents because as children they never socialized us and I think that's a big part of the reason for me and my sister's anxiety and antisocial behavior. My parents refuse to admit that preschool would have been good for us and it ended in tears (on my part) and yelling. My mom who is suicidal just came up to my room and said angrily "have a wonderful life" and I asked her what she meant and she just walked away. I want to save her but I can't and I don't want to deal with her depression anymore. It's killing not only her but the whole family. I can't deal. What do I do about this situation?