Re: testing the house
Years ago when I couldn't figure out why I was having 4 or 5 sinus infections a year, I found some little cannisters (3) on the internet that you put in 3 different rooms in the house.
It's been years and I don't remember where I got them, but if you google "mold test kits", you should be able to find some. As I recall they were to be left out for a certain period open, maybe 1 hour, (it's been to long) then closed and sent to to a lab who would send you a report back.
Each would be rated from 1 to 5 as to the extent of the problem in that part of the house so that you could determine where the problem was originating.
As it turned out my problem was the amalgams, and root canals, not mold so I never had to go through trying to fix it, so I don't know from there if you have a problem what you would do.
Easy, and not to expensive.
Could also be lead, asbestos, gas, dust, radon, etc., so it's a crap shoot unless you hire a professional who can test for everything.