A few things that helped me with the initial sugar crashes and withdrawl
1) drink plenty of water.
2) Keep on you a bag of nuts (almonds/walnuts/cashews/etc) - eat these when you feel weak.
3) Have fruit available - banana, apple, dried dates, etc.
4) Lara bars work well for on the go.
5) eat a nice big breakfast - eggs, bacon, salad, etc. Throw in some sour cream and avocado to get the fat/calorie count up.
6) if you are seriously dogged, a baked sweet potato can help with carb refueling.
For me Carb flu lasted about 2 weeks. I weened myself off the nuts and lara bars after a month. Today I don't even eat breakfast, but I eat a nice lunch and dinner.