Teen Health Advise Needed!!!!?

The normal stereotype for teenagers is... sit on your butt all day... eat burgers and fries for every meal... drink soda... milkshakes... all you do is play xbox or go on facebook... but I'm not one of those and I feel like I'm insanely huge! I'm a fourteen year old girl, 5'11, and weigh somewhere between 151 and 155. I NEVER drink soda, never eat out, never eat fries or burgers, never have milkshakes, but I cannot lose weight. My problem is sneaking bites of things. Like the peanut butter jar will be left out and I'll take a spoon and take some on it and eat it, then crave some more and eat some more of it. I eat a healthy breakfast every morning. Or perhaps chocolate chips will be out I'll eat a handful here and then 20 minutes later do it again! I need to break my habits because it's starting to show in my hair and skin health. I don't want to be fat anymore please help!