MAC - To treat or not

I recently came down with an atypical pneumonia of both lungs caused by pseudomonas aeruginosa. Was treated for 14 days with cefepime. This all happened while I was away from home. The pulmonary doctor in the hospital suggested I talk to my pulmonologist when I got home about the possibility that in addition to my long standing fairly well controlled bronchiectasis, I might also have MAC. I also have RA taking Humira and am therefore immune compromised. 14 days of IV cefepime worked wonders until I finished the treatment. No more coughing or mucus but my breathing has gone downhill since. From seldom needing to use 3L of O2 to almost constantly needing. I'm a 75-year-old female. I went from one small nodule in my right lung (for the past 3 years with no change) to multiple nodules in both lungs. I asked him if I might have MAC and he pretty much cut me off by saying "your too old and frail". He went on when I pressed him on it to explain that the success rate is like 60% at best and many cannot tolerate the treatment. That and the fact there is no guarantee you won't get MAC again. I just want my life from 4 months ago back! Will all these new nodules heal? Is it not a good idea to treat IF I have MAC? We haven't even discussed a bronchoscopy.