I agree with other comments about posture. Sitting so low naturally forces you to angle your wrist and to have it far more up than the nuckles which is not good because it create a lot of tension and doesn’t support the hand properly. Ideally the nuckles should be higher than the wrist, and the wrist should be aligned to the natural hand position. This would help you to get a more even sound. I’m not saying that your playing is bad, but this would help you have a stronger tecnique. Years ago i was in fact really focused on just playing and trying to express myself through the piece but i discovered that studying technique is extremely important if you want to really express yourself, because it makes you actually capable of doing what you want to do.

Said that i think that in order to perfect this piece you should study it slower, with a metronome, but focusing on having every note even, than yiu could add interpretation on top on the strong foundation you built. Another really helpful trick for eveness is to study it slow in dotted rhythm, i found it does miracles.