A Crash to the Ground

Hello. I fell from a height of 2 ft. smack down on cement with my legs stretched out on Nov. 2. I was babysitting my 2 1/2 year old granddaughter and saving her from taking a big step off some bleachers. I'm 67 and I've always been active-- running, swimming and biking-- but mostly running. An MRI showed a subtle fracture of S4 and 5. Both an ultra sound and the MRI show underlying the iliopsoas muscle on the right a small bursial fluid collection. The vagina feels like it is burning and there is tremendous pressure. How long can I expect to heal? (I'm in good health over wise.) I see the doctor again next week. I can swim and bike a little. Running and brisk walking are out. I'm in an out of pain all day but at night, it's very uncomfortable. Is it the muscle, the bone or both? And what should I do to start rehabing?