Thanks for the query.
According to your description that could be bartholin
Batholin gland will be located between upper two thirds and lower one third of the labia minora
When its duct gets blocked it will form a cyst. The infected cyst
will form a abscess
So you once consult gynecologist get examined and take treatment accordingly.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429