Hey! You're not alone!
My sister (jeni here on the Cellar) just had her gall bladder removed two weeks ago (okay, it was a little more - the same day that I was sick as a dog, if you remember that). She also had this awful awful pain in her back and whatnot.
If I were a betting man, I'd guess that's what they're gonna do for you, 'cause that sounds like a stone that's WAY too big to pass. Jen couldn't work for two weeks. Maybe you'll get some PS2 time
I'll point her at this thread so she can toss in her own two cents.