Hi, many thanks for the query!
Well, it sounds like you are having abscess
in gluteal region.
You should get physically examined by your doctor & if its an abscess, then there is no way out but to get it drained.
Regular dressing, antibiotics, anti-inflammatory drugs, antacids, Vit. C preparation with your doctor's opinion.
Also do- CBC, USG KUB, Urine (R/M), RFT.Consult Urologist
if reports are abnormal.
Wish you a good health.