It sounds like it could be a vaginal cyst. Why is going to the doctor not an option? This is a good time to see one. :>)
Possible Bartholin cyst. You have two tiny ducts that lubricate the vaginal entrance. One can become blocked and form a cyst. Sometimes they drain with sitz baths other times they can abcess. Try warm water soaks and if it swells or becomes painful see a physician.
Sounds like a Bartholin Cyst. Warm compress and sitz bath will help.