Boil or pimple next to 😿. Advice?

So I have SOMETHING next to my vag. It’s in the crease where my But cheek comes down and meets my kitty. It’s super sore when touched but dosnt burn and it’s a hard lump like ball(?). It’s. It big, maybe the size of an eraser (in total. Like half is above the skin and half is below).

Has anyone else had something like this? Tips on treatment? I’d rather not go to a doctor unless I HAVE to because who likes spreading their legs wide open for a stranger under a bright light?

Pretty sure it’s not an STD, like VERY sure