UPT is no joke.
First, UPT is a doosey. They're not going to just hand you a set of wings, you're going to earn it. Even in Navy Undergrad Pilot Training I saw guys wash out, even a private pilot/rotar wing civilian pilot washed out. Good luck with your decision and the medical stuff is something to sort out first, but keep in mind that this is no joke and even getting fixed wing isnt a done deal. I knew a guy that flew the H-53 out of Hurlburt in FL.