While raising the mast yesterday I forgot to attach the adjustable backstay, thus the backstay was too short. As I cranked the mast up into position I heard a loud popping sound, looked up to see the top of the mast bent back and quickly backed off. The mast straightened out but now I'm afraid I may have done some damage. Any advice?
I think that the
mast must come down for an inspection. Hopefully, you did not put more stress on it than the backstay and a good wind would. Check the mast for straightness - contact Catalina to determine what would be normal - there must be some tolerance on mast straightness (it wasn't micro-inch straight when it was built

).
I think the bigger risks of damage are the pins at the top and the masthead casting (a crack there might make a pop, it is aluminum & could easily have cracked). Also, check where the back stay attaches to the boat.
At least parts are available. Check
everything mast related & do worry about the 'pop'.
OC