I had a severe cough that came on slowly over time and eventually became severe and debilitating for years. I have been diagnosed with acid reflux, and every time I complain about anything concerning my voice, swallowing, throat, etc it is always blamed on that. One day at work, I was coughing to the point that I was doubled over with it, and a customer asked if I take blood pressure meds. They said they had the same cough and it turned out to be their med. I asked my doc to change my ace inhibitor blood pressure med, and sure enough, within a month my cough was gone. That was several.years ago and the discovery was life changing for me. I am not saying that is your problem, but it is something to look into for many people facing this problem. Sometimes the answer is so simple.