All files gone after consolidating to itunes?

After I consolidated all of my songs, videos and photos, I deleted all of the original ones thinking that those files are already copied and saved to the itunes library. I restarted my computer then was shocked to see that everything on my itunes are gone... like itunes has reinstalled itself. I don't know what to do or how to find those missing files (if they still exist somewhere in my computer). I still have the songs and video on my ipod though. How will I get them back?