320 pounds to my chest and it hurts what happened?

I was playing rugby im 15 and the guy i tackled was 320 pounds. I get low when i tackle so i got his knees and when he fell i got a knee to my chest. At the time i couldnt breathe and everything was flashing white for 15 mins. Now it hurts when i take deep breath or if anythin touches it. He got me right between my two pecs and there is a red mark there now. Can anyone tell me whats wrong?