How to Stay Motivated to Stick to Weight Watchers?

I'm a girl, 14, and 5'6, and got alot to lose! I have been cheating on my diet here and there and feel horrible about it, but just not enough will power to really stop it. What can i do to try to stay on track? They say the suggested weight for my height is 160, and i weigh about 50 pounds more than that, so i got alot to go…

honestly anytime you feel hungry (And you know its cheating) drink a bottle of water first (thirst is often confused as hunger) after you drink the entire bottle (or large glass if you drink tap) if you still feel hungry allow yourself a healthy snack, like a apple, or a small handful of grapes, maybe even a handful of baby carrots. After that if you still feel hungry keep drinking water until your next meal, you may pee a lot, but the water is probably what your body wants more than anything (even if your brain won't stop thinking about the leftovers from lunch)
Just remind yourself this is for you and no one can do it for you, and that you will be much healthier an expand you life expectancy by years. I am so proud of you that you are making the decision for yourself to practice a healthy lifestyle! I didn't do it till I was 16. (21 now)
Cut out the soda (any caffiene really) and potato chips (limit yourself to one small 'unhealthy' snack a day.. like 3 reeses cups minis, or a little debbie snack if you have that urge for unhealthy food, i did that to get my cravings under control, and i would save my snack till the very end of the day so i had something to look forward to for being 'good' and eating healthy / doing my exercises)
Exercise any chance you get to, take the stairs instead of the elevator, offer to get the miscelaneous things other people need.. anything to get you moving and keep you moving. Especially if you're watching tv, during commercials get on the floor and practice pushups/ sit up/ stomach crunches. that way you can build up an endourance during time you normally would be spending on your butt.