Dear Starlah,
There are many things which can cause or contribute to a cough, many of which are listed in the threads below about coughs. Some of the more common ones are: infection, allergies, asthma and/or gastroesophogeal reflux disease. Perhaps if you cannot get your doctor to take your concerns seriously & help you evaluate the cause of your cough(s), you might wish to consult another doctor for a 2nd opinion who may investigate some of these and/or other possible causes. It is troubling to have a cough with persists for months.
Good luck in tracking down the cause(s).
Aloha,
Starion