Sorry to hear you are suffering with pneumonia. You'll need to be patient with your body. Really patient. You'll see incremental improvement but it takes time. A physician once told me for every day in the hospital equals a week of recovery time. So for you that's 5 weeks, plus the recovery from pneumonia.

Practically what can you do? Speaking from experience (recovering from pneumonia not NTM) I can share with you what I did.
-Rest, fluids, small meals. Always be sipping something, warm herbal tea I found comforting as were soups for meals.
- Sleep/rest elevated as I found this helped with breathing
- Has your doctor ordered a bronchodilator? This will help open up your lungs for clearing and breathing
- Continue airway clearance at least 2x daily with hypertonic saline (has your doctor recommended this?) It will help with clearing the infection. You want that gunk up and out!
- Long acting mucinex 1200mg (also check with doctor on this)
- Analgesics (I alternated tylenol and motrin; check with doctor also)
- Use an Incentive Spirometer (maybe they gave you one in hospital); if not available via Amazon
https://www.amazon.com/Incentive-Spirometer-Breathing-Inhalation-Medical-Grade/dp/B0D9K326FZ