Cough from last 2. 5 mnths. No problem.

Hello doctors good evening, i am having cough from last 2.5 months..it all started with fever and cough..fever got cured in days..but this cough has not gone..i am having dry cough.. i have done blood test and xray told by MD physician doctor..xrat was normal and blood test was also normal except lever swelling was found minor.. doctor said it is fine no problem.. he gave me medicines to take..but my cough is still not getting cured...i even went to another doctor but same thing.. i request all doctors here pls just me what should i do.. now i am living in fear that this doesn't turn around in life threatening.. i have left smoking from last 6 to 7 month..and even when i used to smoke it was around 8 to 9 per week.. but from last 6 months i am not at all smoking. i drink whiskey may be 180 ml once in 2 weeks.. pls suggest me which doctor i should go.. i dont have any pain in my throat..nor any problems in swallowing.. only thing is i cough with nothing coming out..