I agree with the 'practice until you can't play it wrong' advice... I recently took a month off from my dulcimer playing , in order to build a new one... and it came out great! However, I took it out to our local open mic in order to show it off, and POW... there I was, trying to play it like I could play my others... without having practiced for a month... Now, my point here is... I had no 'nerves' that night. If I had, I never would have gone on with a new dulcimer and no experience with it. I wasn't too very wonderful...

Nerves are normal. Practice is the answer. Superhuman confidence is the result!
Good Luck, ttr