That just sounds like your nervous man!
I just played some songs at a friends church today for a service and I was pretty nervous. But thats because I didn't hear the songs until our worship band's 2 hour practice before the service! But It all went great once we got up there to actually perform.
My three pieces of advice that have worked for me are
1. Clear your mind of all other things besides drumming
2. Focus your mind and think trough what your going to play
3. Don't try to play anything you haven't absolutely mastered in practice
Hope that helps!!!