Girls please help me?

OK I am in the tenth grade in a military high school in Germany. This is my first year here at this school. I met this girl that is amazing that I play tennis with but she has a boyfriend. She told me yesterday that she was really starting to fall for me but she didnt know if anything could work for us because she doesnt want to leave her boyfriend that she has been with for a year. Another reason why is because she is supposed to be moving next year to the states. She told me that she didnt want to tell me because she thought it would ruin our friendship. But I am so crazy about her she is the main thing I think about, and I don't want to give up on her. There is another girl I play tennis with that I am also going to homecoming with that I like. But Lindsey (the girl that I am crazy about) told me to go out with meagen (homecoming date) but I told Lindsey I dont want to I want to be with you no matter what. SOMEONE JUST PLEASE TELL ME IF I SHOULD GIVE UP ON LINDSEY OR KEEP TRYING:(