Hi Healthgirl,
You may want to check for any water leaks in your home.
These can occur under sinks and behind walls and not be readily apparent for awhile. Also check walls/floors behind/under toilets, as tank sweating can cause moisture/mold issues in some homes.
Look around very closely for any signs.
We clean both the air conditioners in our vehicles and our in home A/C units.
We take them apart and clean them the same way many commercial garages clean A/C units in cars. (We set them up in the garage and air them out for a couple of days after having cleaned them.)
Do you use home A/C? If so, have you checked for mold?
Just a thought.
Oh! wanted to share with you. We find "specialty" allergy/mold products here:
https://www.natlallergy.com/
( I have dealt with this company for over 20 years now.)

DejaVu