Human beings are remarkably inefficient.
It is easy to get discouraged when trying to lose weight, just as it is easy to get discouraged when you are trying to get your finances in order. You make mistakes, you fall behind, you make huge mistakes, and you set yourself back. It seems like you never get ahead!
Here's a clue: Life is Not an Optimized Event.
As human beings, we operate at an appallingly low efficiency level. We waste time, we squander resources, we dilly-dally, we are lazy, we dawdle.
Heck, the average human sleeps nearly half the day, how inefficient is that? Throw in the time wasted getting dressed, showering, eating, commuting - it is amazing we get anything done at all!
On a good day, I suspect, the average human is running at an efficiency rating of 2-5%, perhaps less. Few are operating more efficiently than that, even after taking an "effectiveness" seminar (which just adds to their low self-esteem).
So don't sweat it. The one thing we do well as humans, is accumulate wealth and create things over long periods of time. The pyramids were not built overnight, but over a period of decades. A stone here, a stone there, and pretty soon, you have one of the seven wonders of the world. And sure, they probably cracked a stone or two, which seemed pretty devastating at the time. But look at the results!
So if you are trying to get out of debt or lose weight, don't take momentary setbacks too seriously. Examine them carefully and see if they are part of an overall trend, or merely a glitch on the radar. And then redouble your efforts accordingly.
Life is Not an Optimized Event!