MRSA? Boil? Ingrown hair?

I’ve had this bump on my stretch mark for a while now and just chalked it up to a left over PUPPS. It never really hurt and I just left it alone. Tonight I laid down for bed and had pain when I got into my sleeping position (fetal) when I turned the light on I saw that it was now an open wound and looked pretty deep. I’m freaking out and idk what to do. What does it look like to you? How do I clean it? Should I go to the ER? Should I call my on call OBGYN? Is this even an OBGYN issue? Please help! It hurts to touch around it, the area of it or stretch that leg.