I really need help in everything in general

[Tomatoarereallyyummy]

I have been playing trombone for a good amount of time (4 years) and I still sound really bad. My lower register sounds ok but my higher register (C to maybe F) sounds really thin. I also am cracking on a lot of notes. Does anyone have any really detailed explanations that could maybe help? Appreciate any help and I could provide a recording if it helps or just more info? (Btw sorry if I broke any rules I am new)

[MStarke]

If you can, best would certainly be lessons. There are people on here who can certainly help. If you share a recording - better a video - you may quickly get very good advise, but some of it may be contradicting and you might have to filter which advise you are going to take.

[Doug Elliott]

I do online lessons and can definitely help you fix what's not working.