Know that you are not alone! I think a lot of us on the boards have felt the same way and fallen into the same vicious cycle. Unfortunately, only you can make the decision to do it, to make lifestyle changes and then follow through. Having said that, there are some ways to make your plan more successful. Are you making managable changes or tons of huge drastic changes all at once? Try incorporating some things you know you can do...whether it is cut out one bag of chip or throw away a handful of chips that you would normally consume. Or circle around the store once or twice before you start shopping--maybe this is too elementary for you so you can ignore it but I hope you see what I mean. As you set small goals and meet them, hopefully it will provide ample motivation to make even more significant changes.
Also, try to find somethings you can enjoy to replace the food when the boredom and depression strike. These feelings aren't going to go away no matter what number the scale spits out. I'll be thinking of you...Good Luck...You can do it!