Thanks RJM. I am finally getting to the point I can put it behind me. Turns out it might have been COVID - there was a small hidden cluster of it where I live but tests would not confirm it one way or another this far into being sick. Doctor tells me to assume it is not COVID and do all the same stuff to avoid it as everyone else. Will get the antibody test when it is available just to know. Whatever virus is responsible it has given me great sympathy for those facing the challenge of severe COVID that so many are dealing with at the moment and enormous gratitude for being okay.