try moving [home folder]/Library/Preferences/com.apple.iTunes.plist to the desktop and then opening? Or holding down Option while opening to manually select the library (in case it's a library location confusion issue)?
I've got it working. I deleted everything related to itunes then reinstalled it. It still didn't work so I dragged the program from the HD folder to the desktop and then it opened. I dragged it back to the HD folder and it still works. I have no idea why but it does work now.