My O2 while moving is always 92-94, and my heart rate varies from 106-130 (resting is 98-99%/76bpm.) I keep hoping time and exercise will, but no... So I just ignore it except if I get short of breath just standing still. It's just part of life for me, and for many people I know. My younger brother would be delighted with 94% sats -ever!
As for hair loss - I'll guess stress and an after effect of your illness. Relax and give yourself daily scalp massages...

Just keep on moving - can you put an app on your phone to tell your daily active minutes? I aim to move at least 30 minutes on my walk and 10-15 minutes per waking hour the rest of the day - my goal this week is 250 minutes per day - last week I averaged 230/day, which includes housework, errands, exercise...
Sue