Well you're not alone with stage fright. Many musicians suffer from it. Different people find different ways of coping with it. Terry above seems to use alcohol but I stay far away from it if I'm going to sing. Sure it makes me more relaxed, it also sends my tuning out of whack. I memorize everything as firmly as possible so even when distracted I can still play/sing. I would suggest not trying anything too complicated for awhile until you get your nerves under control. If you're doing three songs start with a real easy one to calm yourself down. Mostly just keep working at it, try to think of the music instead of the audience at first and then expand your awareness to them as you get more comfortable.