Well truthfully the only thing you can do is follow what your heart says, not what you think it is saying or want it to say. Seriously think about everything and follow your own hearts advice, but make sure you still pay attention to your heads advice to and be careful.
Did she tell you why she fell out of love with you? If not she may just be using that as an excuse of some sort to try and cope with some kind of confusion or other feelings she is having. You guys were together for a long time, was this the first trully serious relationship she was in? That could definately cause her some confusion and make her question things, maybe she just needs to be reassured that she is with the right person. Also if this was her first serious relationship maybe she is curious as to what else is out there and what all she may have been missing. Maybe all she needs is a little time to think about stuff and sort through her feelings and to ultimately reassure herself that she already has something trully great and she will come back to you. Remember, love is one of the most confusing emotions if not the most confusing, if her love is true she will be back.
Anyways good luck to you and I hope you pull through this no matter what the outcome.
Remy
