Ok, For The Last 4-5 Years I Get A Cough

Ok, for the last 4-5 years i get a cough from Nov to March, four months of coughing. Ive tried nasal sprays, antibiotics, asthma inhalers, acid reflux meds, nothing works. I do take OTC cough meds, but they make me feel funny. Cough syrup with codeine works, but I hate taking that all the time. I cough til i gag, very strong cough. I need some help or resolution, any suggestions.. Oh, chest xrays are always negative.