Bon, I think you should talk to your doc before stopping the meds. I can't remember if your MAC has cavities? That makes it trickier to treat successfully.
What airway clearance are you using? Maybe you can convince the doc that you will be really, really faithful doing it for 6 months and then have him retest sputum and do another CT on your lungs? Some people hare have been successful in reducing MAC levels and healing lungs, but it is an every day 2-3 times a day therapy - so it can be time consuming.

Maybe worth a try?
Sue

I'll share my experience just to give you some other ideas. I can't remember if you're taking the meds daily or three times a week at this point.
I already had tinnitus when I began my first round of taking Azithro, Ethambutol, and Rifampin daily. On a regular hearing test after about 6 months of antibiotics, I showed moderate hearing loss. My doc stopped the Azithromycin and substituted Ciprofloxacin for the next six months. Then I was off antibiotics for a year or two and had an exacerbation and positive cultures. I went to NJH. Because of the previous experience with hearing loss on azithromycin, they decided to try clarithromycin instead, and just 3 times a week. I've been on it now for almost a year without any further hearing loss. I even tolerated bumping it up to daily for several months when that was needed.
So, I suggest talking it over with your doctors. There may be a reasonable substitute, or maybe your schedule can be changed, without having to give up treating the infection all together.
Wishing you the best!