Cysts On Labia Minora, Painful, Been Depressed. Done Biopsy. Ruled STD. What Is It?

Hi i am currently seeing a specialist from a gum clinic, due to having returning lumps (cysts) on my labia minora, i have had a biopsy proving it is a cyst, and tests have ruled out std's, the cysts are small but very painful and i could have between 1 and 7 at any one time, very hard for the specialist to see but she can just about feel them, but they feel very big to me, they last between 3 and 7 days at a time, sometimes they start to go once they have bled, i used to get them aprox once every 3 months around 10 years ago to now getting them every couple of days, the specialist is stumped and as i am in almost constant pain with them i am really fed up and starting to get a bit depressed, my husband is also getting a bit fed up as i have needed to keep him at arms length for a long time now.