I'm sitting here with two friends who predownloaded the game from Steam, and they are playing the game perfectly. I myself can't play the game, since it has to download the game from Steam even though I have a physical copy of the game. It says there is still 6 hours before I can start playing. Can it really be true that they basically just gave me a useless CD with a validation code to unlock the game on Steam? Seriously, I'm beginning to cry soon! Anyone know how to install it from the CD? PLEASE!

Nope. Have to wait 'till steam gives you the go. Steam decrypts the data on the disc. And when it's friday (where you are) steam will just decrypt the last few pieces which make it so that you can play the game.
Does svck though that you'll have to wait 6 hours. :/

No, it's not decrypting the files, it's downloading the whole game (5735.4MB) So basically the CD could just be empty...