Welcome to SR (:
Your nervousness, shame, and anger with yourself are things many of us have dealt with/lived with and been through. It can be a very unpleasant cycle, with those feelings being made all the worse for thinking "I can't believe I did it -again-!"
I empathize with the envy, I personally spent a long, long time bound and determined that I would get my addiction 'managed' and be able to drink like a 'normal' person.
As tkdan said, there IS a way out, a positive way. Keep coming back, don't give up on yourself!