In my opinion, you are suffering from a throat infection
which will improve with a course of antibiotics. Gargling with warm saline will also help. Please do not worry, but do consider quitting smoking
as it does increase your risk of developing cancer in the long run. Even cutting down on smoking makes a difference to your health. Try to increase the time gap between cigarettes and try to discard each cigarette after just one or two puffs. Avoid being with people who are smoking.