Suggest Treatment For Pain And Bruises In The Back And Buttock

Hi, I fell down my basement stairs 3 weeks ago and hit every step very hard. I bruised very badly. My back, left butt cheek and left leg were black and very painful. Bruising is pretty much gone. I have compression fracture in my L5 and a huge bump on my left buttock cheek the size of a hard baseball. The bump is hard, painful and warm to the touch. How can I get this bump to go away?