photos missing after using Mac OS X install discs

A few days ago I noticed that iphoto was missing from my dock. After searching for hours looking everywhere on my HD I realized the program was some how gone but thankfully when I opened up Finder and clicked on images all my photos were still there. I found my install discs and followed the procedures and reinstalled.

After doing so I found my previous system folder to make sure everything was still there (photos, songs, documents, etc.) Everything was there EXCEPT my photos. When I go to my Previous System folder and click on users and my username and then the picture folder I'm directed to an iphoto icon that says "iphoto library." When I click on it, iphoto opens and the library is empty. If I open Finder and click on images there are about 100 random photos that show (my iphoto library should have thousands)

I'm at a loss and seriously sick to my stomach. Any advice?

Thanks.