I Have A Cough That Won't Go Away, I Have

I have a cough that won't go away, I have tried all types of coughing medication, been seen by a cpn, had an xray taken of my chest. had a five day z-pack that didn't work. took seven days of levefloixin that didn't work and last clinic visit just said nothing they can give me except cough syrup with codeine. had this cold for going on three months