I think that you may have some type of Sexually Transmitted Disease if you are sexually active and not using protection. Disease such as syphilis or gonorrhea. Visit a doctor who will help you.
Hello,
Since you have not mentioned any other symptom, from your symptoms however I would like to rule out the possibility of a boil. A boil, also referred to as a skin abscess, is a localized infection deep in the skin.
Apply warm compresses on the boil and keep the area clean. Drainage of the boil is done only when it becomes soft and forms a head. You can apply Neosporin till that time. Take some over the counter pain reliever and consult a doctor for examination and antibiotics prescription.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.