I've been having this cough that has lasted almost a year and won't go away despite doctor visit. what do you suggest?

See MD : In the US the most common causes of chronic cough in absence of pathology on x/ray physical exam are chronic cough upper airway syndrome formerly known as post nasal drip associated with allergies, GERD, Asthma, and increasingly , pertussis. See MD for workup if history of any of these treat empirically over the counter. Good luck. Also consider smoking, meds, and environmental causes.