I Fell Down The Stairs And I'm In Tremendous Pain

I fell down the stairs and I'm in tremendous pain all on my lower left side of back. I can't stand to sit and vice versa without help and excruciating pain. Same with sit to lie down, when lieing down can't move from side position even moving arms hurts. Can barely walk and lift my left leg as excruciating. Pain is going down my leg. Even with help can't lift my leg.