Bob - ya just gotta stick with it and work through it; it gets better. I've been performing for over 15 years, and I'm still nervous before a gig. I go into this head space I've taken to calling "gig mode" where I'm sort of withdrawn and distracted from the people around me (my wife hates gig mode!), and mentally I'm going through my equipment ("did I forget anything?"), the newer songs ("what's the first line?"), and the general circumstances ("do they feed us at this one?").

By the second or third song, I'm usually relaxing and able to get into the music, be part of the band, and have fun.

Hope this helps.
Michael