How Can Lumps On The Labia Majora Be Treated?

Good day, I'm a 39 yrs old woman, I have a 4 yr old son. I've been having some bumps on my labia majora and also on the smaller ones. They usually appear one day before my period. They get swollen and, if I pinch them, some fat and puss come out. They hurt a lot, and sometimes my lymphatic glands get swollen too and I feel feverish. I've consulted several gynecologists but they say it's just like acne. They've even prescribed some antibiotics but the problem doesn't get any better. This has happened to me since I was 13, almost on every period. Last February my doctor opened one of this bumps and then, he had to continue with a small surgery to take a 4cm cyst out. The bumps seem to get worse if I eat peanuts or any other kind of nuts during the month. What can this be? How can I make this problem to disappear? Mrs. G. / Aguascalientes, Mexico.