Have you tried taking some cough syrup? If not you should. I would also recommend putting some vicks vapor rub on your chest and they usually helps me get rid of a cough.
A vaporizer also helps my coughing by putting moisture into the air and making it easier to breathe.
If you're still not able to get rid of the cough you should see a doctor to rule out anything serious that may be causing the cough to not go away.