I was in a sort of accident....the pain is excruciating?

on thanksgiving i was in a kayak on the river with my two cousins. me and brendan were in one, and joe was in a seprate one. he purposely rammed our boat and i was flung into a bed of oysters. i sprained my wrist, bruised the bone in my knee, and my arms are all cut up. the pain is terrible and nothing is working to take it away. i'm worried about infection too. what should i do?