keepon,
One time, I weighed myself at the doctor's office and found out that I was about 5 pounds less than my goal weight...and then I went home and binged. I still don't really know why. I mean, it was good news, and should technically have inspired me to keep up the good work.
What has helped me in the past is refusing to procrastinate. For instance, instead of waiting for the next day to start a new lifestyle or to start over, I do it immediatly. Even if it's been a really crappy day, I write everything I've eaten down, scribble it out and rip the paper up. Once it's in the garbage, my fresh start begins.
You might want to think about why you feel you have to go crazy before you start anything new. Is your diet unreasonable or too restrictive? Are you afraid that you're going to miss all of your favorite foods?
Good luck!