Hello it looks like you are suffering from balanitis.i.e. inflammation of the foreskin. This could be due to any irritant application, lack of hygiene, diabetes, candidiasis, and sometimes even drug allergy. Candidiasis being the most common. You need to consult a dermatologist so that they can find the primary cause and treat accordingly. Till then eash your genitals only with lukwarm water. Do not use any soaps or antiseptics like dettol.