Airport Extreme Has Green light but MBP wont get connection :(

I am so desperate for help.

Got a new modem today and got it all setup properly. Connecting a cat5 directly to my MBP gives me a solid internet connection.

I turn off my modem and my MPB.

I plug the Airport Extreme into the new modem.

I turn the Modem On and wait for steady lights.

I turn the Airport Extreme on and wait for a solid Green light.

I turn my MPB on and go to Airport Utility and it shows up there as green and when I try and connect to the wifi it wont give me any connection.

I have been working on this for HOURS. Shutting this off shutting that off waiting waiting powering on restarding unplugging etc etc etc and I am at a complete loss as to what to do now.

Please please someone help me!