You're dead-on to the age and the weight I was a year ago! (You've got an inch on me, though!) Consider me the shrunken, future ghost of you.
I went slow and steady for 2012 (average of 2~lbs a month, almost solely through diet and not exercise), and though the pace felt frustrating, I kept at it. I've never been as light as I am now - not even when I was 12 years old.
Don't worry so much now about the final end point - I still have no idea where mine will be. Just keep trucking on with your changes. Slow and steady WILL pay off for you, ultimately! And bear in mind that the smaller you get, the more even small losses will be apparent - so don't be discouraged if you don't see a lot of difference with 11 lbs lost so far. If you're not already, I suggest getting a tape measure and taking your measurements once a month so you have a progress indicator besides the scale to go by. Good luck! Hope you're here like me, in a year's time, looking back happily.
Edit - I want to add that actually believing I could really lose the weight was a big deal for me. It's part of the reason I've had trouble setting a goal weight. Like I said, I was heavier than this at 12 years old. So learning to trust myself and believe that I can be this smaller person is a huge learning process. And my only advice is that there's no magic solution except plunging forward and living the behaviors that lead to a lower weight. Focus on the habits and behaviors - remake yourself and your outlook - and slowly, the question of whether or not you can do it just melts away.