Sounds to me like you have a boil (very angry pimple). If it is not INSIDE your vaginal area (between the lips), you can use a warm compress on it and see if you can squeeze it open or use a sterile needle (sterilize with fire for a few seconds) to try poking a hole in it. If you get it open, there will be a large amount of blood and pus that comes out: it is the pressure of this yucky stuff that is causing you pain. Other wise, see your doctor and have him drain it for you. Also do not attempt to open it if it is between your vaginal lips: that one is definitely for the doctor. It will need to be kept drained by squeezing it daily until it stops draining, otherwise it will not heal. Blessings - Blu
Okay so this is what I would do if I were you; I'd soak in a HOT bath with some salt in it to really make sure you're cleaning that area. Then dry off and just rest a warm wet wash cloth on it for about ten minutes. That way your pores will open and you'll be able to tell if it's an ingrown hair or a pimple. Which I'm sure you know how to deal with. However, if this lump is on your minora labia, white/yellowish, hard. Sorry to say but you've got a bartholin's cyst. They're caused by a blockage in your lady seman glands. So the fluid builds up and eventually form a lump. Some situations that arent so bad, women will just get up on some intense antibiotics. Or for the onces that aren't so lucky they have to go and get in drained.
So in other words, I'm hoping it's just an ingrown hair or pimple! Good luck!
It may be a bartholins cyst. You could try warm sitz baths to see if it helps. If its indeed a bartholins cyst you may have to have an in office procedure done to get rid of it. I hope you feel better soon!