What helps motivate you to stay on track?

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So, here's the deal... I'd lost a total of 60 lbs. I gained 10 lbs back over the course of about 1 year. I've been maintaining that 10 lb gain and 50 lb overall loss for about 5-6 months now. I want desperately to lose those 10 lbs, plus 10 more. The problem I keep having is my willpower to just say no to food that will throw me off track. I have an excellent few days, an entire week... and then I have one "bad" thing and I just keep going and I keep telling myself "Oh, what's one day... what's one weekend. As long as you don't gain more then who cares??"
But I DO care. I feel terrible on those days I don't eat well, and on those days I keep telling myself to remember how I'm feeling now versus how great I feel when I eat well... yet that doesn't seem to help at all. :( The taste of the food overcomes my will to say no. On top of that I've always been a stress-eater and I've certainly been stressed over so many things as of late which is NOT helping.

So I'm wondering, what type of motivation does everyone use to help keep their minds from wandering to that delicious donut, or that quick & easy fast food? Photos? A phrase you can refer back to? ANY suggestion is helpful!