You will soon find out that it is VERY EASY to stick to the diet, for when you dont your body reminds you.
Feeling nauseous is liver issues, eat less, drink more and take care of your liver. There are quite a few tea that will help and some black radish extract (ask your local health store for liver support herbs and treatments.
Dandelion/ artichoke/minth tea are good options for liver support.
Hot drinks stick to the stomach, cold goes right into the bowels so avoid cold when eating.