I always find that the first three days are the hardest. If I can knuckle through three days of good clean eating with zero sugar intake and zero refined carbs intake, then I'm good to go and it no longer takes will power. My will power gives out on me pretty quickly too.
I suggest a multi-vitamin for fatigue and a diet rich in vegetables and lean meats and maybe tell yourself to give three days. That's it. Just three days. And after three days I bet it will get easier.
As for snacks, think hard boiled eggs, string cheese, roasted veggies, yogurt (I like Greek), half a sandwich, leftovers from dinner, slices of deli meat, handful of nuts, small salad...those are my go-to's.