Lump between vagina and butt

I have spot right between my vaginal area and my butt. It sweels up (no discoloration) but then gets a little painful. I have been trying to feel around to figure out what it is. So far all i can say is it is under neath my skin on left side of me and is in a kinda rode shape? and it goes down to my anus opening or that is sorta what it feels like it does. When it sweels and gets tender and painful I have squeezed and pushed on it. Sometimes I get puss out but this time around I got a bunch of blood out of it some kinda clotted looking. You can feel pressure inside my anus when i do this and the liquid runs out of my anus. Any Idea what this could be or who I should go see about it? I went to mu gyno once and he said he couldn't really feel nothing at the time but I think he sould have felt my back butside to feel it plus at that time it was very small it is bigger right now thanks Julie