It is essential to get an early check up and tests done for proper diagnosis and treatment .
You may get a culture /sensitivity test of the discharge from the soar.
get your blood sugar tested .
a course of broad spectrum antibiotic like kefmax o cv i tab 2 times daily ,rolosol 1 tab 3 times daily,zincovit
1 tab daily may be helpful .
5%solution to clean the area and apply betadine ointment and cover with sterile dressing
hope the lesion is not due to any drug reaction .
and get examined
hope you recover soon