Your sound is coming along! I know you have a slight back injury so don’t over do it this week–try for short practice sessions (5-7min) focusing on mid-low range playing. Work on the Low F study (first two-three lines at least). Aim for getting a consistent sound throughout–remember you might need to adjust your air to get the same volume in different registers.
Remember to ALWAYS breathe through your mouth–you proved to yourself that it helps you sound better!
We do NOT have a lesson next week due to something at TFS so I’ll see you again on the 15th!
Here’s the link to the music theory I would like you to review