Drink plenty of spiced lemon tea, no milk but a quint of honey. Protein supplements work as well, if you know what I mean. Make sure to wear the correct trainers and sports sock because spoprts socks are good for sport you see
Make an appointment with an Ear, Nose & Throat doctor. He or she will put a tube down your throat, don't worry, with a little anaesthetic you won't feel a thing, and have a look to see if there is something there causing you to cough.
If the ENT finds nothing, you may be referred to a gastroenterologist to look all the way into your gut.
These two investigations are critical in determining what you may have.