sledding accident causing back pain and limited motion.

I am a 36 year old female who foolhardedly went sledding down a steep hill this morning. I went down fast, caught air off a bump and hit the ground hard- first my lower back, then my head. I couldn't move my back for several minutes. After a few more minutes lying on the snow, it became easier to move so I carefully got up and slowly walked back to the car. As I was driven home I turned the heated seats on for a few minutes. My lower back hurts and feels very stiff- I have limited range of movement but this seems to be getting better. I have taken a painkiller and am lying down for awhile. I'm not experiencing numbness, tingling, or bowel/bladder issues. Can you tell me if there's anything else I should do/not do, or if there's any reason to go to the emergency room? Thank you.