Cough for more than 1 month. Got worse in the past 10 days, more yellow phlegm, chest pain, low grade fever. Chest X-ray & blood mormal. What is it?

See a doctor. You have some type of inflammatory process in progress in your respiratory tract, possibly chronic pneumonia, potentially due to tuberculosis, aspiration, fungal infection or some other form of inflammation. You should make a list of your temperatures, associated symptoms and see a doctor asap. If you know an infectious diseases expert so much the better. Good luck and hope you are better soon.