i have a sore lump on my labia majora and has been there for about 6 months to a year. over this time it has grown to double the size and has started to hurt a lot recently. it is like a pinple but a lot wider. i don't want to go to the doctor unless i have to. it cant be any STD's as i have only slept with one person and the guy has only slept with me. please explain what it is and what i should do.

kind regards