You might have Vagus Nerve damage, that makes your throat very sensitive and the smallest tickle will make you cough. I have both LPR and vagus nerve damage. My cough was unbearable and for over 30 years it went misdiagnosed so nothing helped. Two years ago I finally found a doctor that diagnosed me correctly and saved me. I am on amitriptyline (Elavil) that helps with the nerve damage. Check out the voice institute of ny. It has some valuble information that will help, and of course ask your doctor of the possibility of the nerve damage, but don't be suprised if they tell you no, only because they do not know anything about it.