Emotions...lost of a beautiful girl friend/boy friend

I had a real close relationship with a beautiful and understanding girl friend who wanted to become a man. I don't know how it happened but we just seem to "hit it off" and were attracted to each other. I have never experienced anything like this before and it was wonderful.
She (he) has found another girl and appears not to have feelings for me anymore. It hurts knowing I am losing her and don't know what to do. Living as a girl now has been confusing enough but to have found someone who I love and now losing her is something I don't know how to handle. I never thought I would ever have this happen to me.
I don't know if this has ever happened to anyone else. If so; I need your help and advice.
Please help me.