Well done, lots of good things in that video, yes you have obviously been working hard! You already know what you are good at, so i will just offer some constructive criticism you can think about or choose to ignore
It would be worthwile for you putting on a drone and playing scales in different keys and tonalities over it veeeeeery slowly just to hear exactly where each note sits in tune with the drone. In that performance, a lot of the slower parts were not in tune. To my ear it was more often sharp than flat but it did vary throughout. The most obvious one was the very last note. You overblew a bit and the sound spread out, kinda going thin and very out of tune. Put a drone on Bb, play a Bb major over it, then Bb minor, harmonic minor, melodic minor etc... then change key. It will really help settle your pitch and i think it will help fill out your sound a little more also which could resonate a little better.
The other thing that stuck out to me was that whilst the tempo in the fast tonguing sections was reasonably steady, your precision of which note you were playing i think could have been better. A lot of the fast sections lacked claity of pitch, i could hear the articulation, but not necessarily the note behind it. Put the metronome on very slowly and practice nailing every single note in time, with a quick and precise slide and crisp articulation. If you split a note or an articulation is not as clean as the last, do it again. Do not settle for anything less than perfection. When it sounds fantastic at a painfully slow tempo, raise it by 10 clicks and repeat the process. Do the same until you reach a fast tempo you want to play at. If you have put the time and effory into doing that properly, we should be able to hear every pitch in the fast section VERY clearly and that would be impressive, rather than a good articulation sound but with ambiguous pitch center. If you listen to lindbergs recording of this, you will notice you can always hear EXACTLY what he is playing. Everything is very clear and precise, whereas most other recording of this on trombone that I have heard, do not pay enough attention to making sure they are in fact playing ALL the notes exactly as they are written on the page.... a lot of recordings you hear the players will kind of "fake" their way through it which is much less impressive.
Well done again, I think if you address the things I just mentioned you have the potential to be a very impressive player.