Hi, After reading your history it appears to be the problem of sebaceous cyst . Sebaceous cysts are the collection of cheezy material surrounded by a wall. The treatment is by excision of the cyst. During excision if any of the part of cyst or the wall is remaining can cause recurrence and infection in the area. You must see a doctor and preferably a surgeon to rule out any abscess at the area. For the time being period you to apply plain antibacterial cream such as fusidic acid or mupirocin (latest is retapamulin) and to take pain killer tablet by mouth for reducing the intensity of pain and redness. The only precaution you must follow is not to touch, pinch pop or squeeze any of them other wise it can get infected and can cause complications. Take care.