Help! I have a massive sore "down there"...?

So on the front parts of my privates, like where all the hair is, I have a huge swollen pink sore about the size of my thumb. It's incredibly tender and I've accidentally bumped into it twice today and I teared up it hurt so bad. At first I thought it was just an ingrown hair or something since it's bikini season and I've been doing a little maintenance. What do you think it is?