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The present swelling of perineum
you have mentioned might be due to the soft tissue injury
or a bony injury ( Coccyx injury) due to the fall.
Th swelling you have experienced in the past is called furuncle ( Infection of hair follicle). Warm compresses in the case of furuncle makes it soften there by it ruptures quickly.
But warm compresses in the present condition would just rlieve your pain temporarily.
As i have mentioned earlier the present cause can be either soft tissue injury leading to perineal hematoma
or bony injury.
If the pain is mild and your activity is not limited by the swelling. You can just use NSAIDS or specific antiinflammatory drugs like serratio peptidase, trypsin and chymotrypsin
or combination of both.
If the pain is severe i would strongly recommend you to go for an X-ray of Sacro Coccygeal bone and if possible Ultrasonogram of Perineum which would rule out the possibility of Hematoma or a fracture
Wish you good health