Hey it happens, I've fallen on and off "the wagon" so much its crazy, but i think one key point is to find the things you CAN stick to and hold onto those. Sustainable change might be drinking more water, even when your stressed... drinking more water is something you can usually work in. My eating habits are not always the best, but for me, I've built going to the gym three (plus) times a week into my routine, its non optional at this point and while I haven't lost a lot of "weight" I'm the strongest I've been in years. Forgive yourself for bad days, bad weeks, bad months... and just keep trying. At least that is where I am at.