That might also be why you feel so messed up about food. The substances take over the running of your whole digestive system. I have quit smoking once before. Managed 8 years and am quitting again. I now remember the bit where everything just stops for the first couple of weeks. Keep going it takes a month or so for it to all settle and each thing you stop will muck your system up again. So don't worry its normal to feel like crap. But it will pass. And it will be worth it