Musician's Lull, Like a Writer's Block

As a musician, you will have days where you can play anything, play it fast, expressive and perfect. Why everyday can't be one of those days I don't know, but I'm having the complete opposite today. I've been working on a piece for my auditions and contest for months now, for some reason I can't seem to get a single run, I've hit so many wrong notes it hardly sounds like the same piece and I've reverted back to old habits with rhythms and fingerings. It is so frustrating with my first audition in 14 days and I feel further away from being ready than I did yesterday. What if one of these days happens the day of my audition? I'll be done, I won't get in, let alone get scholarships. These stupid musician's lull days put me in a terrible mood. I could just scream right now.