Taking care of perineum
If this is the case:


you can use a stool / chair or stadium seat
you can use orthopaedic cushions to added comfort
if sitting is a problem you can use another poster like lying down (don't use a cosy or luxurious bed as you will soon fall asleep. A hard surface may be best using a Yoga mat perhaps laying beaded seat cushion on top even if this causes you to fall asleep.)


Also when meditating try to keep your attention a bit longer in this region looking at the arising and passing away of sensation equanimously. Don't think of any healing or removing discomfort. Just keep your attention on the sensations. If this is Karmic, reducing your mental reaction for sensation resulting from karma means you will not be adding fuel to the karma prolonging it's results. If you react with any thing, like disappointment if any issue pops up, being happy when something does not pop up, etc. You are adding fuel to prolonging the ailment.