It will pass.
But it SUCKS to go through it, I know.
It could be your period, it could be a bit of kickback from Thanksgiving, especially if you ate really clean and passed over some treats or sweets that you wanted. Are you going through any particular stress right now that might trigger a craving?
The best thing, especially if it's a sweet/carb craving is to break yourself away from it as much as possible. It's my experience that giving in to a sugar/carb craving just makes it feed on itself - your blood sugar spikes, your insulin production goes into overtime, then your blood sugar level plunges, and you're hungry again ... and it's a big vicious cycle.
Hang in there and resist.
As my mother used to say: This too shall pass.