Why are we all so fixated on perfection? Doesn't the very definition of "perfection" imply that it cannot be achieved? Sure, there's always an area where we could improve, but programming our minds to look for flaws, just so we can beat ourselves down about them is anything but productive. Instead of striving for constant perfection, let "progress" be the driving force behind your actions.
So what if you're not at your goal weight today? Rather than list out all the negatives of the situation, develop a plan of attack to get you closer to where you want to be, one day at a time. After all, progress isn't about being "perfect" in the moment; it's about consistently moving forward and being better than you were yesterday (mind, body, and all).