Hello! This most likely sounds like a condition called- Bartholin's cyst-abscess which is an infection of one of the glands in the vagina- usually causes extreme pain and fever. This has to be treated by a gynecologist as one of the complications could be that the pus collected inside could open up on its own. I suggest you visit a gynecologist as soon as possible and get it checked.

Hello user this could be bartholins cyst kindly get your self examined