I perform for a living and seldom if ever get nervous.....that said there is nothing like the buzz of being the centre of attention and hearing people applaud when you finish. No drug can touch that. The main reason people get onstage....and why most people overcome shyness and fear is to hear that applause.
Contrary to popular belief.... an audience wants to like a performer.... they want to be entertained and have a good time..they are quite forgiving and understanding especially for someone just starting out especially if you smile and show humility. You in return can only give your best and that means practice your act till you know your stuff inside out.....if you do THAT then both you and the audience leave happy. The more you perform the easier it gets. In a year or two you will wonder why you ever got nervous in the first place.

http://www.soundclick.com/bands/songInfo.cfm?bandID=687727&songID=5238055