Upgraded to Itunes 8 and now airport won't work at all!

So I finally upgraded my Itunes and everything was working just fine for a day. Now for no reason I can think of when I pull up Safari it is saying I am not even connected to the internet, while my airport is telling me it is connected to my network. When I checked my network status it says "Airport is connected to the network (my network). Airport has a self assigned IP address and may not be able to connect to the internet". I NEED to figure this out! It is driving me crazy. My roommates computers (both on wireless) are working fine, and the only think I can think of that changed is my upgrade. Maybe I need to upgrade my airport software? I have NO IDEA as I'm not too computer savy. Any help would be awesome... I'm hoping I'm just an idiot and this is a simple fix.