Good suggestions all. Thanks for contributing, helping others.

At the recommendation of my doc (no longer in practice) after my first bour of COVID I upped NAC to 1-600 mg. cap both AM and PM - if breathing gets bad (bad cold, etc.) 3 caps/day. I take 12-hour Mucinex at night, 600 mg. if breathing is kinda OK, 1,200 if it isn't. Also, Robitussin-knockoff (guiafenensin, same drug as Mucinex) cough syrup, liught f dose, to get the med to the tissues immediately to break up phleghmy cough.

Also: Quit dairy and wheat!!! Maybe corn, too. I was miserable until I did - wasn't allergic until post-COVID kicked it off.