Don't worry about it. I assumed that you were busy with school. I know how Hogwarts can be and since Al and Severus didn't show at the house warming either, I guessed that things were a little more chaotic than usual.
I'm not sure how anti-social and thinking that people are shit are related. People are shit, that doesn't mean you have to have to avoid them, just learn not to tell them what idiots they are. Really, it's easy once you learn.