my problem, in a nutshell

1. "God I feel fat and disgusting. I have got to lose weight. Jesus, these pants are even tighter this morning. Did I gain weight while sleeping?"

2. "Oh look, a donut."

3. "I'm not going to eat that donut."

4. Eats donut.

5. Repeat steps 1-4.

Or, come to think of it:

1. "I dislike [bad behavior], dislike myself for doing [bad behavior] and want to stop doing [bad behavior]."

2. Opportunity to [do bad behavior].

3. Decision to not [do bad behavior].

4. I do [bad behavior].

5. Repeat steps 1-4.