So, I've had a few days off and its getting a little better.
Doing the ever so famous self diagnosis here because I have a PhD in doctoral stuff and such.
Anyways, if you find the bony arc in your arse the pain is right next to that.
Dont know if its my sciatic nerve, an abdominal muscle or glute muscle thats causing it. Glutes would make sense because it hurts when I squat.