I'm a wannabe comeback player, returning at 65 after having left the trumpet early in high school. I expect to be flamed, since my question focuses on range, hints at impatience and exposes that I don't have a teacher.
The usual practice materials (e.g., Arban, Clarke CS) assume a range to A or higher. I can hit these notes unreliably, with lip stress and rapid fatigue. Therefore, it seems to me that I should focus on lip strength in the range of G - C above the staff, so as to be able to work the standard exercises.
My question is how to do this. Should I concentrate on pushing high notes as hard as I can? My lip is quickly exhausted and good for nothing else. I would appreciate suggestions.