Sounds like you hit the low carb flu or are experiencing a withdrawl from some chemical your body has become dependent on. Don't force yourself to eat 3 meals a day if you don't feel like it. Eat some potato when you get hungry to help you nix the nausea. For goodness sake don't eat junk (like CW pizza) thinking it will fix nausea!
Potatoes, fruit, white rice if you need it. Don't eat out of habit. Make sure you don't have a stomach bug!