I think you and traded a few messages when I was dealing with debilitating mucous a few weeks ago (I was up all night, trying to breathe, crying, certain I was dying). I am better now (still have some mucous), but it is less and has become manageable. My pulmonologist did long and strong blast of Prednisone with a long taper (and that knocked a lot of the mucous out). Now he has me on a long, strong course of Doxycylene (and after two days I’m seeing more improvement). I’ve started taking 1200 mg of Mucinex 2x daily, plus NAC. Though I tested negative in late December, like you, I think I may have had Covid in Sept/Oct. When I think back, I felt terrible back then; soaking night sweats, chills, fatigue. Anyway, not sure of your resources or insurance, yet when I was in that really bad place ... my next plan was to get myself to Nation Jewish in Denver, or to Mayo in Jacksonville (I could drive there in a few hours). Though I am doing better, those are still options if I slip back to that miserable place. Best wishes and keep us posted.