I knew a girl who's broken-hearted over a boy who could not share his feelings. She really loved him. And I know a boy who could not say just three little words that would make her day. It hurt her, though he really loved her.
If there's a lesson to be learned it's a hard one to take; once it falls apart it's so hard to unbreak, so don't you ever make that mistake.
Tell her you love her.