I need inspiration to continue to exercise? Please help?!

I am trying to lose weight.. I'm almost 16 years old, and I am 6'0 and I weigh about 180.. I want to lose 20 or 30 pounds. I have no problem working out, like jogging (on treadmill or on wii fit -lol) or taking my dog for a brisk walk for 20-30 minutes, but after a week to two weeks and I don't see myself losing any weight, I lose inspirtaion and I just quit... or after a few days I lose inspiration because losing weight is hard... any ideas?
-please don't leave links about stupid medicine or weight loss secrets, please, I want an answer from a real person, that's not trying to sell me anything... I just need inspiration..

thanks :)