Yea man. I hear that. Thats exactly what I do/did. I used avioding social situations entirely, and putting my head down in school. I get my social interactions though computer games anymore, there no risk no embarrsment, and it's fun. It's not healthy, the amount of time I spend playing and I don't suggest it
I don't have a problem with alcohol. My Dad is an alcohol, I've seen what it does and I've made a pact with myself to never touch it, ever.
I would suggest trying to get invovled in things. I got into pro cycling and like to watch and read about it all the time. And I got into a robotics club and met a great girl in there that has helped me open up a lot. So try to meet new people and find activities that you enjoy. Might want to try working out some. It will make you feel good about yourself and thus other people will think good of you too.
PS: Try to lessen the drinking a little bit. Liquid courage won't help in the long run.