Here's a Daily Spark Blog that I think may help.
I would encourage you to take some time to journal where you think you started letting go of the habits that were helping you maintain the loss. If you can see that in the big picture, it will help you next time those triggers appear.
I always encourage people to consider the difference between a life alter, and a lifestyle. It took me years of yo yo dieting before I figured out a lifestyle that I can maintain. Remember that if you do what you always did, you'll get what you always got...is that something you want?
Start fresh and figure out a lifestyle. Eating (and drinking) is 80% of the picture and you typically cannot workout enough to compensate for a bad eating routine. How can you eat better tomorrow?