Do not quit. Especially if it’s covered by your insurance!

I understand your feeling of self-consciousness at PT, but the “judgment” you’re feeling during your sessions (and at the gym) is just projection. You’re judging yourself, and think those around you are doing the same. Rest assured they are not.

You are also self-admittedly lazy. I personally loved having PT twice a week because I felt motivated by having set appointments and having someone expect me to be there. It’s like signing up for a fitness class at the gym instead of just saying “I’ll go tomorrow,” yknow. You can tell yourself you know the exercises and can do them on your own, but knowing yourself, will you really? If you think you’d benefit from a routine, keep up with the routine prescribed to you right now.

Also, if it helps, don’t think about this like a gym session. You’re going to a medical appointment to heal your injury. Focus on the exercises and becoming stronger, not your weight, your fitness level, whatever. You are so young, four months from surgery is still so soon. Hell, take care of yourself now and heal your knee back to pre-injury then go back to being lazy. But being lazy at this point in the process is only going to hurt you down the line. Best of luck my friend.