Getting over a first love is really a hard thing to do. It hurts so bad, and you never feel like you are making any progress. To get over someone, you have to want to get over them. You can't just go along loving them and expect a huge change to occur one day. You have to stop allowing yourself to think about her. You need to find a way that you can control your mindset, and to take it off of her. I know nothing I say right now is going to help you drastically, because I know how bad it hurts to lose someone you love. All I can do is try to help you through my own experiences. Understand that you are insanely young still. Hardly anyone finds their life partner at your current age. Everyone has to go through a hard breakup, consider yourself lucky that you had it early enough in your life that it didn't do much damage.
You need to take your past experience and grow from it. Relationships make you both stronger and smarter. If you are able to get past this, your future relationships will be much more stable, and much more fulfilling. The key thing you need to grasp here is that 'anyone can get over anyone'. I hate to be a damper on romantics, but there is no such thing as someones one and only soulmate. People are extremely replaceable, and the sooner you realize that is the sooner you will be able to move on and get on with a healthy happy life.
I'm sorry if I didn't exactly say 'happy' things in here, but I'm trying to be completely honest. Realize that she isn't the only girl out there and move on. You will be much happier once you do.
Good luck, and if you ever want to talk to me about something, you can PM me.
-Holly