I wouldn't know if your O2 levels are too high or not, but in my case I knew 100% was high because normal for someone living in my area at this higher elevation is low to mid 90s. But the way I brought mine down was through the frequent breath hold exercises to slightly increase CO2 levels.

Interesting about your LPR. The inflammation seems to indicate there is some sort of reflux going on, but I suppose that could be do to other conditions. Many people on this forum have a GI issue like reflux, so there may be a connection between that and breathing but I'm not sure what that connection may be. I do have a hunch that inflammation in general may play a part in breathing.

Do you notice the air hunger occurring mostly when you're at the doctor? You mentioned it happens when you're sitting around - is it worse in doctor settings? How about sitting vs lying down?