Had a cough 7 week now,some occasional sneezing,occasional smoker, chest xray came back all clear gp said it virus could last 6 month?surely not?

Bronchospatic change: It's unusual for an infection of any sort to cause, by itself, a chronic cough lasting weeks & months without change. Do you smoke, have asthma or some allergic disorder? Is the cough dry or do you produce mucus or phlegm? I suspect you have no fever. If cough is worse at night, it may be due to acid reflux. Continue to investigate, even if it means seeing a pulmonary specialist. Hope that helps.