Maybe you should stop thinking about "dieting" and start thinking about making lifestyle changes. Eating is an every day thing, not a "work week" thing, making yourself start over every Monday, just might be setting you up to treat your diet like a job, and apparently it's a "take this job and shove it" situation? We all have those days, believe me.
I started by eating whatever I wanted, but logging my foods and analyzing my habits for 3-4 days. According to one of my best friends (who also happens to be a nutritionist) you can't make a lifestyle change until you know the what/why/when/with who, where and how of your eating habits. Then I worked on getting rid of my bad habits one at a time. The first week I started exercising every day, not a lot just 15-20 minutes/day. The second week I gave up eating 3 breakfasts, and focused on finding ideas for eating one satisfying healthy breakfast. Breakfast was my worst habit, which I would never have known without the 3 day exercise. Then I worked on finding healthy snacks, figuring out how many calories was right for me, then finding out which combination of carbs/fats/proteins was best for me. So forth and so on. This week I'm trying to get back in the habit of drinking lots of water because I haven't been really good about that lately.
I also have been doing a wellness program called the 5, 10, 15, 20 Challenge which is a daily thing as well, not a weekly regimen. It's 5 servings of fruits and veggies/daily minimum (I always go over that), 10,000 steps on a pedometer, 15 minutes of strengthening exercise per day (1,500 calories or less if you're overweight) and 20 stands for 2,000 of your 10,000 steps have to be aerobic. That way I have daily goals for health and wellness that have nothing to do with eating rice cakes and lettuce for lunch.