This is a bit of a personal story but, I'm sharing because I think it's important to find what's motivating you and keep it in the forefront of your mind.
I have a 4 year old daughter and we have been trying for another child since she was 11 months old. We have been unsuccessful at even falling pregnant. The only thing that has changed is my weight. I was 100lbs lighter when I fell pregnant with her than when I started this DietBet.
My heart has broken time and time again and it has always been in my mind that it's all my fault because I gained so much weight and I grew to resent myself for not doing more to get rid of it.
Now when I think about why I'm doing this, in additional to my daughter, I say the "names" of the children that I want. I only really want one more, based on my age, and I've been known to pick out names ahead of time. So when I start to doubt myself or I look at something I shouldn't be eating, I repeat my daughter's name and the name of the child that doesn't exist, but I'm hoping so badly for. Over and over in my head. And it helps keep me on track.
That's my motivation. What's yours?