I've always had thin hair, but while on Prednisone (also had radiation for thymoma), I noticed got even thinner. I've been off the Prednisone for 3 months now, so hope it gets a little better.
It seems like you have experienced almost every bad side effect that MG and the meds can cause. You must be some tough guy to handle it all. I know it gets you down at times though. Don't know how I'd deal if I were in your shoes.
Hang tough!