I am a senior in high school who is in his fifth year of playing the trumpet. As the marching band season ended, I have been having some new issues plaguing my playing . These include an airy tone, using an excessive amount of mouthpiece pressure, trouble playing any note above 4th space E (I can play it easily, but for some reason it is a lot more difficult now), and trouble articulating notes above 4th space E clearly. My tone just seems to lack response, as if no matter how hard I try I cannot a clear buzz and beautiful tone. Are there any exercises, books, routines, etc. that I can do to try and get my "old chops" back? Thank you.
PS- I practice for about 1-2 hours everyday, with equal amounts of rest per amount of time actually spent playing.