What got me through and back on the band wagon [after quite some time feeling REALLY depressingly sorry for myself] was making a list one day. I listed everything about my body I wanted to change and why, listed all the people who would be proud of me and all the people I wanted to make jealous, listed all the health benefits to losing weight, and most of all, I listed what losing weight would mean to ME. It really did the trick.
Best of luck. Once you get yourself in the right mindset, nothing can hold you back