It really is a problem when you lose focus and can't seem to find it again.
I've been stuck for a few weeks in that same mode, although I've been on Phase 2 for some time now. I restarted Phase 1 today and am feeling fairly dedicated right now, but I'm not sure what the difference is.
Here are some suggestions - not sure which is at work for me right now, but something has changed my mood:
Buddy up - find a friend who gets it and confess.
Oddly, when I opened my mouth to say "I've been stuck lately" she opened her mouth and said the EXACT same thing at the same time. It was good to feel like I wasn't alone in my struggle and to have someone around to brainstorm ideas and possible causes.
Be prepared - chop veggies, store some quick on plan foods in the freezer, spend the money for a favourite veggie even if it's off season.
Get inspired to cook - look at a cookbook, magazine, web site or specific cuisine and challenge yourself to adapt a recipe to be on plan for whatever phase you're in.
Get inspired to exercise - have a look at strongwomen.com and read some of the short newsletters there. I print them off and put them into a binder that stays in the bathroom. It's my reading material lol!
Focus on the positive. What a good body you have - even if I don't like my current shape, I have to respect the body that bore two beautiful children and that manages to stay strong in spite of the abuse I've heaped on it.
Whatever the time of day, get back on track - don't fall for the last supper, start tomorrow, finish the week and start fresh stuff. If you've strayed at lunch, have the on plan dinner you intended and have the dessert too. Get back into the routine as soon as you can. Don't spend time justifying or recriminating either, just move forward.
Have a good talk with that inner child. Sounds odd, but sometimes my struggle is internal with the adult knowing what to do and the petulant child inside resisting what is best 'just because'. A gentle confrontation, often in the form of a journal entry, sometimes does the trick!
Hope some of that helps. As I said, I'm not sure what is working but this was my all-out assault.