I am curious if you might benefit from being accountable up front rather than after the fact. For example if you shared a food plan for the day, rather than reported on how "good" or "bad" you were. That can be so subjective, especially when you are in it.
I also find that for me when I am struggling it if sometimes less about food and more about lack of sleep, feeling overwhelmed etc. Thursdays tend to be the hardest day of the week for me with food for that reason.
Lastly I am curious about what works in the beginning of the week for you? Why does it work? Sometimes building on my success is the best way for me to go.