Welcome here on Health Care Magic Dot Com.
I am very much concern of your problem.
I think I will certainly able to help you out of this condition.
In my view you are suffering psychological trigger cycle of cough
You have to break this cycle to get rid of this problem.
I will suggest you to break this cycle by your will power, so as to order your body, not to respond to these stimuli of neurological origin.
If you need, you can take help of some mild mood elevator.