Anyone get sick for months?

I started teaching this year in a very small village where the kids have very poor hygiene and the school itself is moldy and very old. Since I started to work that school, I had pneumonia first, took antibiotics, then I had 10 days of holidays and I was just doing fine when I don’t go to school. But 3 weeks ago I started working again and I’m having terrible cold, like I am cold and freezing 24/7, nose stuffed, my face hurts from the tension, I think it’s sinusitis and even my gums are swollen and hurting. I get enough sleep and try to eat healthy but sometimes I eat sandwiches with my bare hands at school, will stop doing that. And usually take the bus for school so yeah… feeling really, really miserable for being this sick for 3 months straight. The whole weekend I spent my holiday with swollen throat even paining to talk, stuffed nose and it makes breathing so difficult I started sleeping breathing through the mouth and it makes my sleep quality worse. I truly don’t know what is happening to me. And feeling so frustrated