Often, before playing the bass in a concert, I'd feel half nervous and half excited. To shift the balance in favor of excitement, I'd reason, "I've played this music many times, so it's unlikely that I'll suddenly forget how to play it during the concert. Also, this isn't a solo recital. I'm just one of many people who'll be onstage. The bass is a supporting instrument, and I won't be carrying the melody of a piece, typically, so the pressure's largely off there. Also, most people in the audience won't know this piece as well as I've come to know it."
Getting into that mindset paid off for me and resulted in my feeling at least reasonably satisfied after each concert.
