I rarely get sick and haven't been sick since making this healthy living lifestyle change. So I can't relate or give advice there.
I do go through a similar phase, however, when I'm stressed. It is almost always around exam time in my classes. I get stressed and just crave bad foods. Part of it is that I feel like crap so I don't want to go home and cook something. Part of it is that I feel like I "deserve" it since I'm going through such a rough time, have done so well for X days, blah, blah, blah.
This time around, for the first time ever, instead of going to McDonald's or Wendy's or Pizza Hut when exams hit, I went home and made a double portion salad. I still felt like I was indulging because it was so much more food than I usually ate for dinner. But it was healthy, and I didn't wreck my day because of it. I also felt sick afterward, which made me realize, hey, maybe your stomach isn't big enough to handle this much food anymore.
It is an excuse. You have to think about how you're going to feel
after this is over. Will you think
Gee, I'm really glad I ate all that junk food! It helped me heal and was just so delicious!? Or will you think
Guh, now I feel worse and I've gained some of the weight back I worked so hard to lose! What was I thinking!? For me, after that exam was over, I was patting myself on the back for sticking to my plan, eating healthy, studying and kicking butt. Stay strong!