how can I breathe easier in my room without a window?

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
=/