Can definitely relate to the problem of derailment - so you have my total sympathy & understanding.
I fasted on Mon & am doing today as well. Yesterday, I had 2 slices of toast, one for breakfast, one for lunch - which is actually an improvement in itself as before discovering 5:2, I would have sworn it was illegal to put only one piece of bread in the toaster!!! Despite having toast at lunch, the naughty voice in my head told me to polish off the last of my son's birthday cake......as the Tupperware needed washing! Honestly, it was not a small piece....I cut it into 3 pieces to eat it.....stuffed my face rather more quickly than I should (probably thought "eat it quickly..before you have time to come to your senses!!!")..........and the sad result was...guilt, shame...slight anger, great dollops of disappointment and a horribly over-full feeling in my stomach
I then continued the downward spiral later on in the evening........5 crispy duck pancakes (yum) followed by a family bag of Galaxy Counters......groan. I have absolutely no idea how many calories are in such a bag.....millions probably
I only buy the family bags because they work out much cheaper than a single serving bag......but sadly I lack the willpower to restrict myself to, say, 8 Counters & no more! Clearly an "all or nothing" kind of gal!!
The simple fact is, these bad habits will take me time to unlearn because I have had them for soooooo long. Any day that I don't do it will be a triumph (though I stick religiously to 500 cals on fast days, no problem) - that's the way I am looking at it.
So, cut yourself a bit of slack maybe, but try to look into why you do what you do. Personally, I am trying to fill a huge emotional void...that really can't ever be filled anyway! The trick will be to replace food with other, healthier, non-food things. But what might they be? Answers on a postcard please................