these feelings won't go away

It was the third grade we were in the same class. The second I saw her I knew for some reason I will be with her for the rest of my life. We use to take the same yellow bus together home I would sit across from her and I would always smile when looking at her but never brought up the courage to say something. Until the 5th grade when I wanted to show her how I felt about her I wrote a letter about how much I love her. Those were the happiest times of my life. When valintines day came I bought her a fake rose I thought this will seal the deal. After school with a big smile of my face I get on the bus and didint see her I looked all over. I ask about where she was, my teacher told me she moved to florida. I was crushed only in the 5th grade and I had these feelings. So 8 years later I find out she moved back and from that day I knew I will never let her get away. We went out she told about her boyfriend who proposed to her and how she is still in love with him. Even after hearing this I go out with her anyways and gave her the fake rose that was in my bathroom that reminded me of what I onced lost. These past days felt like the longest of my life. We talked until we fell asleep we went on webcam when ever we had the chance. I really opened up to her I told her how I really felt. Finally I kiss her. I thanked god that day for bringing her back to me. Then she gets back together with her "fiance" as if nothing happened. I think that she might have been just afraid to show how she really feels about me because of her being engaged, I don't know what to do, these feelings won't go away and it hurts just thinking about her. I just depend on time to pass my grief I suggest you do the same.