THanks for sharing Larry, I was really shocked to find out that post was from you at the end. I've always thought you had great technical skill up there and have never thought you look nervous. I would say concentrate on your breathing while playing, it may take your mind off the moment as well as help you relax. Try to focus on your breathing in rhythm with your playing a few times and see what the outcome is.
I had a great time playing last week and have really enjoyed the class much more since we moved into the new location. While bluegrass has never been a favorite of mine, I certainly enjoy the playing together aspect and laying down good rhythm for the leads to dance on. My greatest weakness is the lack of discipline while at home to learn any of the leads. I know I can do them, but it obviously takes proper practice time to learn them and I've been a slacker. However, the joy I get from playing rhythm really does trump all that. I wonder if we couldn't get a good jam session over a fire pit sometime!
When in doubt, slow down, breath, remember to smile, and the rest is just small stuff.