Hi Ive Had A Cough For The Past Few Months.

Hi Ive had a cough for the past few months. On a day to day basis it changes from a dry cough that leaves me gasping for air to a phlegmy cough which cause a pain the centre of my chest. Its bad particularly at night, in the morning, when I'm talking and when i exercise. I exercise 5 times a week and would say I'm fit. Please helpppp