iphone trouble

What do you do when you accidentally delete EVERYTHING on your iphone?
This is really really bad. But at the same time I kind of like not having any contacts in my phone!
Is it really pathetic that the only number I have memorized is my parent's cell phones?
Let me tell you the story of how this happened... late last night I decided I wanted to download the Invictus motion picture album (great music), so I do. And then I decide I'd love to have this music on my iphone. Well it just so happens that I hook up my phone to my computer and it asks if this is a new iphone or if it's "Whitney." Duh it's Whitney so I click on the button saying it'll sync or whatever. Bad idea. I definitely should have read that more carefully. I kind of forgot that was my ipod "Whitney." I disconnect it after I realize my mistake and yup, my iphone is now the replica of my ipod. No contacts, no messages, no pictures. All is lost.