How can I get over this girl?

Ok it's a messed up story I was talking to this girl then we like dated and I fell in love with her and she told me she loved me back well after we went through some ruff stuff we ended up apart... Well she was talking to me again and right before I thought we were going to get back together she started dating her ex, well i still love her and we still talk and see each other but it kills me what should I do I know I can't make any move on her and I don't know how to get over her