I hurt my knee sledding and it won't stop hurting!?

I went sledding with my brother yesterday (I'm 13 and he's 12) and we were going down the hill in our back yard. I was going down the hill just by climbing on my sled. But my brother wouldn't stop bugging me to get a running start to go farther down the hill (although I was going farther then him already). So after about the 8th time of him asking me I did it. I started running...running...I got to the hill...and jumped down towards my sled. But my left leg was not positioned correctly and instead of landing on my soft sled my knee came down and my knee SLAMMED into the iced ground. I then flipped over and landed on my side. I wasn't able to walk on my leg because of the pain and it was so weak from the impact. So I was carried into the the house by my Dad and after about 30 minutes I could at least move my leg. It got all swollen up and when I bend it, it feels like there's a crap load of pressure in my leg that's stopping my muscles from moving all the way and it HURTS! Today it is still swollen up like last night and still hurts like hell. Any idea what I could have done to it and how I can stop the swelling etc? Thank you!