Im going thru almost the exact same thing and I am also 19. My fiancee broke up with me 3 months ago. We were together for a year and a half and planned on spending the rest of our lives together. But my situation is a little different- he just doesnt want to be with ANYONE right now. And we're still good friends and we hang out 1 or 2 times a week. For a while things got distant between us and I know that he became annoyed with me calling him and asking to come over. But over the past couple weeks things have gotten better and we've sorta become close again.
Anyways, just so you know, you are definetly not alone. I spend each and every second of my life in tears over him and am going thru the most intense pain anyone could ever feel. I feel like there is nothing left to live for. Deep down I almost know that we're gonna be back together eventally and that is the only thing that keeps me going. I wish I could tell you that things are gonna get easier with time but then I'd be lying. The pain of losing the one you love never goes away. But maybe it'll be different for you. All I know is that for me the pain grows even more intense with time. The only advice that I can give you is that if it's meant to be then it'll be... eventually. Many couples break up (sometimes numerous times) and end up getting back together. Keep hope is all I can tell ya. Most people prolly dont agree with what I said but if you truly love somebody I dont think you should give up.