You might be overdoing it. I’m a comeback amateur player, played a lot in high school and early college. Dreamed of going pro and took from some reputable teachers but didn’t have the chops, so majored in business, got married and had a daughter. 25 years later (daughter turned 10 today), no regrets. But I have limited time to devote to playing trumpet. I try to play everyday, but don’t always get a chance. Realizing lately that that is likely what’s holding me back from progressing faster to the next level.
But I’m happy with where I’m at, I can pretty much play high C whenever I want and can go up to E pretty well.
Tightening the corners into more of a fish face is how I do it, although I have found less movement is more–I try only moving as much as necessary and that seems to help. I don’t go too crazy, but less is more.