Air Purifiers

My chest really hurts. My landlord had cleaned the mold problem in my room. But I find it hard to breathe in there. But I also went a little crazy cleaning with chemicals such as tilex, a great value disinfectant, and I sprayed perfume because I still smelt mold. I haven’t cleaned the carpet yet or my stuffed animals, could the chemicals and my stuff be the reason why I can’t breathe well? Or is the mold in the walls?
I also have an air purifier with a hepa filter, should I change the filter?
It really hurts to breathe and Ive been in my moms room for now, but I really want to go back to my room.
I have the door open and a fan
still no hope
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No central air or heat, so in winter windows are cracked and in summer windows are screened but opened. I bought the air purifier to help with allergies and after 2 nights it does seem to help, but think I need to go back and get the larger one. This one is for room 10 x 12 and my room is 16 x 13 and is connected to kitchen with no dividing door. Am I fighting a losing battle, or will this unit help pretty bad allergies (I think mostly to dust)? Would love to hear your experiences.
P.S. I bought the Holmes brand with Hepa type filter.
Thank you.