The symptoms you are complaining are suggestive of nicotine withdrawal symptoms. After smoking withdrawal it is common to have these symptoms such as throat pain, throat dryness, foreign body sensation, black sputum sometimes associated with cough and headaches. Usually no specific treatment is required. You need to avoid mouth gargle. Drink plenty of fluids such as juices and tender coconut. Take
vitamin c tablets. Usually within two months of nicotine withdrawal you should be normal
Next Steps
Consult nearby ENT specialist for confirmation of diagnosis and appropriate treatment if required