There has been so much good advice shared already that all I can add is "ditto ditto ditto".
I love the one about the terrible 3s. I thought that was well-written. I did make it past my third 3 and I agree that once you get some of the original kinks worked out things do settle down. I failed on one of my first major ventures outside of my comfort zone too. I felt really ashamed of myself and bitterly disappointed too. However, I did get right back on my food plan and within a few weeks, it felt like it had "almost" never happened.
Now, I feel like I can do this, more than I have ever before. Remember, we are all shaking loose whatever it was or is that got us fat in the first place. Each time another aspect of our old ways falls by the wayside, we have acheived a personal victory. Becoming aware, as you have shared here, is one of those victories. We applaud your honesty. Next time, you will do better. You really really will!