Ah, yes, motivation. You are definitely not alone in that struggle.
Have you read any of the SparkPeople articles about motivation? That might be a good place to start.
Do you have anyone around you that can serve as your buddy? Maybe it's someone that you can share your goals with and who can help you along the way. Perhaps it's even someone that you do exercise with or someone you can call when you're having a tough day with nutrition. If not, there are plenty of people here.
SparkPeople also has some motivational quotes (a couple hundred to choose from) that you can print and post around you for motivation.
We may all be at different points along our journey, but we're all here together on the same road. It's a great place to ask questions, and to share your ups and downs.