Talk to General Physician on Wheezing And Dry Cough

I have flu since late November (sometimes runny, sometimes clear). Now , it is dripping down the throat. I have little congestion. Phlegm not coming out is causing wheezing. What tests should I undergo in order to diagnose the underlying problem as antibiotics, prednisone and salbutamol has not helped (all taken as separate treatment from other)? Kindly recommend diagnostic tests + xrays for sinus, asthma.