Help

Hi, I love someone who's a really good friend and she says she is interested too but not ready for a relationship, we get on so well and have kissed a few times, she says we should just take it one day at a time but this has been going on for about a year now. My problem is that I help her so much with lifts and lent her money I've now got a feeling I'm being used and the reason she wont commit is she is keeping her options open, it's doing my head in so much that it's making me depressed, what should I do?