If you feel so sure of her love for you, its best you try to talk it all out with her as you have anyway been doing. If she is willing to respect your sentiments and see how both of you could work together to improve the situation, then mybe there is a ray of hope. But if you constantly give some excuse to justify her behavior, something is definitely not right.You simply have to be realistic and face it. I don't think any third person can mediate unless both parties are willing to listen. I know you are- but what about your girlfriend?