The illiopsoas is both muscles, it's composed of the Illacus (purple) against the illium of the "hip" and the Psoas Major which is the red muscle. It attaches to what I'd call the posterior femur (lesser trochanter). It has to attach to the posterior to be a major flexor of the hip like it is.
If you have a predisposition to hernias it's very possible that's the issue, and it's not going to get better until it gets repaired. You can afford to miss the time, and don't be stupid and try to squat until it's properly healed.
My money is on inguinal hernia. It is, however, possible that it's something like the Illiopsoas that's pissed off, it's not uncommon.