Hi lesley355,
I just read your comments. My suggestion is to make an appointment with
your family doctor as soon as possible. A lump in your genital area would
be very painful. Also any mysterious lumps that suddenly emerge and are
getting bigger need to be talked about with your doctor. Good luck, Eve :)
It sounds like an infected Bartholin's gland. They can get very large and painful as you describe. You may get it to drain by itself by soaking in a hot bath. If not, and if it becomes too painful, you'll have visit your doctor and have them drain it. Good luck.