Well done on your first two weeks - that's a great result!
As for keeping motivated it can be daunting if you have a lot to lose, and it sometimes seems like you will never get there. So instead focus on smaller, achievable targets and give yourself non-food rewards when you reach them. You might want to make every stone with mini-rewards for the half-stone awards. Some people get facials, or manicures, others might buy themselves a book or whatever it is that they enjoy. This way your next target and rewards is only ever a month or so away. The losses will soon mount up if you stick with it. Keep reminding yourself how long it too to put on the weight. It didn't go on overnight so really anything quicker than that is a big plus.
The other important thing is variety. If you eat the same things all the time you will eventually get bored. And boredom is fatal because you will invariably end up falling off the wagon and reverting to old habits. Also your body gets used to you doing the same things so if you want to keep those pounds coming off then you need to keep challenging it with new things all the time. So variety in everything - different plans, different meals, different foods, different healthy extras. This is another opportunity for you to set yourself mini-challenges and rewards, like having at least three new meals every week, or trying a new food every week. This will help keep your interest up because there is always something new to try.
Then there are the non-scale victories that will keep you going those weeks when the scales just don't want to move, no matter how good you have been. Remember to take your measurements and repeat this every month so you can see yourself getting smaller. I remember one person saying that they tied a piece of string around their waist. Then every few weeks they put it on and its a visible reminder of how many inches they have lost.
Exercising is another one because not only will it help a bit with your losses (although perhaps not at the start when people can be known to retain fluid) you will see yourself become fitter, having more stamina and being able to do things that you were never able to do before. Seeing these little wins will help keep the motivation levels up. Some people choose to train for formal events like the race for life or the moonwalk, but for others it might just be something as simple as being able to walk to the shops and back, to walk the dog round the park, or to take the kids to the theme park and fit on the rides.
Good luck
