How can I stop being socially awkward and aggressive?

I think the key is to find stuff you love, that you are interested in. Then not only will you naturally be around people with the same interests, and obtain what it sounds like are much-needed social skills that can ONLY come with being around people and experiencing naturally progressing friendships, but you will have stuff to talk about with other people, thus becoming more interesting. Try out different activities/groups at school, or join an activity outside of school. Art class maybe? Learn to play the guitar? And relax. Get comfortable with yourself. People can sense it when you are not relaxed, and that's what creates the social awkwardness.

Calling yourself an boring aggressive snarky wallflower wont help. And, as you describe it, my guess is that is not that much an ability of speaking than an ability of listening that you should give more attention too.

And please: stop calling yourself names too.....