Inter religion marriage.

I am a guy aged 27 yrs, loved a girl (presently aged 25) truly from past 8 years. She too is a awesome girl, loves me a lot still but the problem is we belong to different religion and the girl's parents are not in agreement to this. I convinced my parents and they accepted this and even went to the girl's house to speak but the girl's parents refused. I have done a lot to the girl emotionally, financially in fact sacrificed a lot, professionally as well. Now the situation is such that the girl doesn't want to marry against her parents wish. I feel cheated and my life is ruined. I want to fight this out legally now as it is a do or die situation for me.