I have used drugs of all kinds and alcy in college. And right now I am back in college but sober. Oh, and I have big problems with social anxiety.
When first getting sober a couple of years ago, I thought that I was a lot more fun and cool when wasted and that I couldn't have fun with people unless intoxicated--I was wrong. In my experience, my perception of how socially smooth I was in my old days had more to do with the fact that when I was high I felt inside like I fit in (it doesn't mean that I actually did). Those relationships built upon getting wrecked together have faded, not only because I stopped using, but because once I removed the drugs I realized that I had nothing in common with those people. The friends that I have made since sobriety, on the other hand, are more meaningful.
Obviously, the social anxiety stuff can be a drag but if you stick around sobriety for awhile I think that you will find it easier, I know that I do now.
Good luck.