It looks to me that you have muscle damage at but cheek as well as thigh. You may have a crack in bone but chances are very less still i would suggest you to get a x ray
of pelvis to make sure that every thing is alright with your bone. Also i would suggest you to Sit in tub filled with gentle warm water two times in a day. This is called sitz bath. Take Brufen
and Myoril tablet and Diclofenec ointment at your back. I can assure you that you will be fine in short period.