Maybe you have already written this somewhere and I missed it.....do the symptoms you are all experiencing get better in a different environment ? Might be interesting to see what happens if you are away from the place where everything started. Do you have pets, and are they healthy?
Are you in a position where you could be someplace different, even if it was a camper in the summer months, just to see if any of you begin to feel better once away from your current environment.