|Don't you keep a back up of your Outlook data file on your PC? This is usually called outlook.pst and resides here on Windows 7 & Vista:|
C:\Users\<your user name>\AppData\Local\Microsoft\Outlook\outlook.pst
You are supposed to keep a backup of it at regular intervals so if disaster strikes you can easily restore all your folders and messages.
If you don't have a copy of it I don't know what to suggest now.