Thanks for telling the truth, but I suppose you are not telling the full truth. However this may be a case of infection of fungal yeast or Candida albicans infection. It may be a case of yeast allergy which is general in men having high blood sugar. Other causes may be due to infection through sexually transmitted disease. In any case you should immediately consult a doctor preferably a sexologist. Notice if during sexual intercourse you have pain at the head of your penis. This may also be due to anal intercourse or heterosexual activities. Till you see the doctor, gently wash the head of your penis with warm water at least twice a day, but do not add any disinfectant.