it mighth be a bartholin cyst.
Take a sitz bath 3 times a day if possible Fill the tub or a basin about 4-5" of warm water. Add 5-6 drops of tea tree essential oil. Mix some epsoma salt into back and then squat in the water for 15 min .
Also, you can make a paste with tumeric and tea trre and apply directly to swollen area . reapply when necessary.
hopefully between the two things it will allow the cyst to drain. if it does not drain on its own, you will need to see an obgyn and have it professionally drained.
Sending healing energy to you