Do you have a chimney? What about the ceiling, have they checked that?

I hope you can have an expert come and check it out. If they do use bleach at any point, that is not good to breathe in either, so make sure you are gone!

A dehumidifier is great, which we use in the rainy months, but the ultimate solution is getting rid of it, wherever it is!

Have you tried using a mask for when it's really bad?

Also, have you had your radon checked? It doesn't smell but it is harmful and quite common.

There are people whose immune systems are sensitive like that. You might need to take precautions around any smells, so as not to put more of a "load" on your immune system.

Annie