From your description it does sound like either an ingrown hair, a simple cyst
or a Bartholin's cyst.
I would advise you not to try opping it as this eill cause further irriation and also expose the region to reinfections.
Please wear a sterile pad, take several sitz baths with warm water and epsom salt and apply warm compresses to the region.
But the main approach would be to visit a doctor and get examined, as your diagnosis could be more tricky than is being assumed here.
Hope this helps.