Practice lip slurs and practice with a bigger mouthpiece in addition to your other methods of improving your range and you will be able to play much higher
Nothing's never hard its all in your mental I was playing level 5 music in 1 year after beginning band and its called PRACTICING btw each and ever day at least 20 mins to 8 hours each and everyday slowly at a time!!! Yall got this!!! :) ;)
I'm only in my second year and I've flown through orchestra level music like it's easy. I wrote a cover for a Jurassic Park theme called Journey to the Island and it had multiple trumpet parts from the real song, in original key and octave, and I can play most, if not, all of them. This song is like a warm up to me I don't have my trumpet rn but I could sight read this.