Sounds like a pinched nerve and you just slept on it wrong.
Two of the more useful tools I've found in the weight game is Ibuprofen(sp?) and muscle rub. Once you start putting up some serious wieght, you realize that there are things out there that make life a little easier. Of course you're young so I would stay away from "helpers" like that for a long, long time.
As for your situation the Cryotherapy sounds like a really good idea.