Try this on your next new piece.
- Find a professional recording.
- Listen a few times while watching the score.
- With pencil in hand work out the fingering for both hands on nearly every note. You can skip repeated notes.
- Now back to the recording. Listen to the 1st phrase, typically 2-4 measures. Using the fingering you wrote down. mimic what you heard. Make adjustments to match the expression of the professional. If you are playing jazz, make adjustments of the notation to match the recording. The recording is correct. Fakebooks are approximations.
- Continue to the end of the piece, painstakingly working out one phrase at a time.
- Next day start over. It will go quicker today.
- As you go along, record your phrases and listen back. Are you shaping and articulating correctly. Don't worry about the tempo. That will come later.