I guess it's obvious you have not backed up or anything. One thing I can think of is to install a complete ROM that has the camera in it.
I'm currently using peachsunrise by Jocala. There are others. Also, Jocala posted the factory ROM, so you could just flash it to factory if that's what you prefer.
It's a process, though very quick and easy once you understand it. Search for the Exhibit II wiki at XDA to get instructions and links.
And then backup as soon as you get it right again. Nandroid is great and Titanium backup as well.
Cheers