Sounds like all-or-nothing thinking to me. So you've eaten...have you really blown it? No. You've just eaten. Yes, it feels like the end of the world but no, it doesn't mean that you have no choice about whether to eat or not this minute, the next minute, tomorrow, or next week.
Perhaps you could do the "Consequences of changing / not changing this behaviour" exercise. Write it out, it's so much more powerful when you do.
If weekends are your downfall (they were my difficult time too), plan your weekends. Write your plans in a diary or on a calendar and look at them. Keep yourself out, about and busy and remember to do things that you enjoy.
How about writing some goals for the rest of your day today? What are your goals for your weight, your health and for having fun? But most importantly, what is your goal for changing your thinking and being kind to yourself?
I was tootling along too, up until yesterday afternoon.... I have to break this cycle of not getting thru the weekend somehow....
