I won't go into my woes with my recent troubles...LOL!
However, take it from me (and I recently went through same thing you're going through) the only way to get over it is to do it. Best thing to do is start rehearsing with the band, and once you guys are accustomed to each other, you'll start relaxing with them. And then if you can play a small party for friends/families and be surrounded by people you know - you'll find it's easier that way. Once you do that, you'll start feeling more comfortable on stage, and realize (as Tonetele said) you can focus that nervous energy into playing.
I just recently played an outdoor show in front of hundreds...huge stage, wireless...I watched a DVD of us and I was all over the stage. My kids were there (they're adults) and said they couldn't hardly get a photo of me, every time they'd go to take a picture, I was gone. I had a blast! It was huge fun.
As for my playing skills, I still have a lot to learn and re-learn. I'm still playing "catch up". But I'm getting better. The band has even said they can't believe how much better my playing has gotten since joining a few months ago.
Stick with it, Tom, and keep us posted on how you do. Good luck to you.
"Just once I'd like to hear you scream in pain"
"Play some RAP music"