One of the best and most relaxing things you can do is to go out with great frinends, eat and sing. Even if you cant sing, dont worry most of the others cant either. But that is the point. If everyone could sing like a pro, then it would be nothing but a chicken strutt competition, and where is the fun in that.
So go relax, make a few new friends and have a brew. Smile. Your most likely better than me, and better than you thought.