Sensitive teeth after cavity filling?

I had a cavity filled this morning on my last top left molar. I didn't have any pain or sensitivity in my tooth or the teeth around that one before the filling. The tooth that had the filling seems to be fine, but all the teeth on that side top and bottom are extremely sensitive to anything hot or cold and chewing hard things hurts. It feels like I have cavities in all my teeth. then after i ate a granola bar today I had a massive ache in my gums and in the teeth. I figure this is not normal. What is going on. it has been exactly 12 hours since they did the filling. I'm scared its never going to go away. Please help!