Thanks forum friends, I know you're right and perfect play is not something I should be aiming for. I would just like to play the piece reasonably smoothly and with minimal wrong notes. I'm having that familiar experience of playing the piece so many times that I'm growing tired of it, so I will take a break now and sleep on it. Maybe I'll get a reasonable recording tomorrow.
I can't imagine how professional pianists cope with the pressures of live recitals... their experience must be a thousand times more stressful, I don't know how they do it.
"Don't let's ask for the moon, we have the stars." (Final line from Now,Voyager, 1942)