Am I the only one to stutter whie playing an instrument

Am I the only one to stutter whie playing an instrument I have been playing the tuba for 7 years at the conservatory, and I have a fairly good level, but I sometimes have stressful or difficult pieces. I noticed that when I was apprehensive about playing a fast or complicated part, I had the same blockage in my mouthpiece that I have on the P's, and the same horrible tension. So I wanted to know if this happens to other musicians, or people in other activities than specifically speaking, and how you manage these special "stutters".