there's an old saying among jazz players...."when you make a mistake, repeat it"
then you work with it and "pitch your way out of a jam" to borrow a term from baseball. And to borrow another baseball term, "When you're swinging for the fences, sometimes you are going to wiff"
I always encourage people I play with to take chances. Even if you bust, there's something about just trying that raises the energy of the group. And as a performer, part of the mental preparation is to accept that mistakes are going to happen, so its best to just put it behind you and get on with it quickly when it does happen, and if you perform enough, it surely will.
sort of like the old joke about there being just two kinds of performers: those that get nervous and liars