Instead of futilely trying to will yourself just to be more motivated or positive, think strategically.
Maybe you just fell off the wagon, so to speak. You were planning to eat well, and, well, you pigged out on junk food instead. You're hardly the first person to experience this kind of setback. But to you – right now – it feels like this "failure" marks a U-turn.
Here's the thing, though: You don't have to think of it that way.