Lumps - really worried please help ?

Before I had a painful lump was about the size of a pea about 10 months ago next to my vagina in the crease of my thigh and vagina and I went to the doctors and he put me on some tablets for a few months I never thought they did anything but the lump gradually went, but now its back and is about the size of a cherry tomato and is very painful I can barley walk, what could this be ?