I have been trying to lose 10 stone for nearly 6 years now. My motivation kept running out, and I would be back to square one. I had my second child in december 2011, and I realised that motivation is always going to come and go. i cannot depend on it. I have too far to go, and I cannot expect the initial thrill of weight loss and the end goal, which is going to be years down the line, to keep me going. I had to commit to my weight loss. It took me a whole year to lose 2 stone last year. I am a slow loser. If I was depending on motivation, I would have given up long ago (and have given up sooooo many times). But I'm halfway into my second year and 2lbs away from my 3rd stone. I have so far to go, but I am commited to it.
There are a few things you can do to get you going again and the ladies have given some brilliant suggestions. But going by my own experience, its commitment that will get you through the struggles!
Maybe post here how you are feeling and we can help perk you up and make you want to do this again!