Hi Maggie,
I'm sorry you are hurting, I know when I was engaged to a girl when I was about 24, it took me a good year to get over the loss of the relationship. I lost weight, would wake up in cold sweats, and had trouble eating for the longest time, but if you love your self and try to move forward, in time the pain will lessen and you will be both stronger and wiser from the experience. The main thing you need to know is that you need to love yourself, and do what is good for you and to lean on your friends and family. If you have a good friend or mentor that can help you through this, that would be a good thing, maybe someone from a church you belong to, a school councelor a pastor or elder that you trust would all be great. I hope you find your happiness soon.