Help! I have fallen totally off the wagon!

Look at your calendar, pick a day one week from today (or heck tomorrow even!), from that day forward you are BACK on the wagon! Set a goal for yourself, pick out a book or movie and say "I will buy myself this ONLY when I hit my goal of sticking to my goal for 2 weeks SOLID". Now, make an action plan: This is what I will eat for so many days, and STICK TO IT. It's just for 2 weeks right? You can do 2 weeks!
Set yourself up for success instead of thinking it'll be an automatic failure by buying healthy foods. Some of the biggest wins were when I just decided to do it even though I wasn't on track the way I thought I should be, and I wasn't feeling ready or on track.
You have the knowledge, just take one step. For tonight set a date!

What wagon? It is just normal life. Sometimes you eat less and sometimes you eat more. You need to eat less more often than not. You don't need to eat less everyday. There is no rule that requires you to make streaks. Can you think of a day you had in your life when you ate less unintentionally? Well it's exactly like that. There was no wagon when you did it. People who maintain naturally a healthy weight also sometime eat less and sometimes eat more.

Every day is on its own. There are no streaks and there is no wagon. Everyday you make a decision to eat less or more. Just make a decision to eat less more often.

If you plan to stay at a healthy weight for life you need to forget about wagons.

Rid yourself of the idea that there is a wagon. There is just you, moving along. You can't fall off you. If you take a step away from your destination, you can always make the next step a step toward your destination. If you take seven or eight steps away from your destination because, hey, there's some pretty flowers over there that you want to pick, it's OK (assuming there's no sign that says "please don't pick the flowers"). Once you've got the flowers, you can always make your next a step toward your destination. Next time you see some flowers, before you walk toward them, ask yourself whether those particular flowers, at that distance out of your way, is worth the delay in reaching your destination.

OK, maybe I should have gone with a metaphor of you driving on the highway. Is getting off the interstate to drive 20 miles to see the world's largest ball of twine worth the fact that you won't reach the motel where you're registered until 90 minutes later than you otherwise would? The decision is yours. There's no right or wrong answer, just the answer that you can live with today and tomorrow.

Focus on not gaining any weight, make that your priority. Just maintain. Stay where you are. Then, get to a good place, take your deficit and grind it out.