Firstly, you need to understand the underlying dynamics of fasting. Any kind of fasting is going to bring out the cravings... because these are nutritional/dietary issues you and your body needs to deal with... If you can over come them, by the time you reach the finish line, many of your cravings, if not all of them, will be tremendously diminished and your tastes for foods will have changed to the point of disliking many of your fave SAD foods. Believe it or not. It's true.
The thing is, you need to find distractions, you need to keep an open mind, you need to educate yourself about the dynamics of fasting, whether it be water, juice or dry fasting. That way, when issues like cravings, or healing crisises occur you have a battle plan.
Many people believe fasting is a physical thing, it's about the body and that's where it begins and end and they are so wrong. Fasting will effect the emotions and spirit as much as it will effect the body. Cravings are of the emotions. They are connected to the emotions.
When one goes on a fast, so much more happens than just the loss of weight. The body detoxes, it heals and rebalances, it rejuvenates. When it detoxes and rejuvenates, that includes the mind, emotions and spirit.
Whenever I have cravings, I suck on a spoon of honey or drink a cup of hot fresh lemon tea with cayenne pepper. These cut the cravings for me <snap> that fast.
It pays to plan ahead of time for incidences such as what you are going through right now. I make sure I have plenty of new books to read. You may want to get some new music, candles, incense (for the spirit) plan a new garden, things like that, to distract you from fasting issues and to stroke your spirit.
I have done three 30 day juice fasts and many two week juice fasts. Juice fasts are so incredible. You heal and rebalance the body, you rejuvenate the body, you lose tons of weight, you clarify the mind and purify the emotions and can evolve the spirit.
Please do not quit, just revise your plan.
I hope you succeed in your endeavor,