Hello! I'm 22, I want to get to 150 ish lbs eventually! I'm trying to get there slowly! I started off lots heavier than you. It can be done, it can it can, I think the biggest thing for me was realising that MacD's and BK and KFC is really junk. It's just not good food and really, when you've been eating healthy, it doesn't taste good either!
I also recommend exercise! Make friends with your local gym/pool/exercise class. Cultivate a crush on the cute gym instructor/kickboxing instructor *dribble*
Feel free to PM me if you want a support buddy! Otherwise these boards are a great source of inspiration and support!
Good luck with your life change / weight loss journey / diet, whatever you want to call it.