She sounds like she could possibly be bipolar or have borderline personality disorder. Right now she may still care about you but she is also trying to figure out more about herself. She may be holding on to you for fear of abandonment and by letting go of you she will be stronger and better able to judge her true feelings for you. This is a good thing because if she stays with you just so she's not alone your relationship will be like a rollercoaster. If instead, she gets to know herself better and then decides she wants to be with you because she cares about you, then your relationship will be much stronger and healthier.

All you can do right now is read about Bipolar and Borderline Personality disorder. You may want to ask her if she knows her diagnosis and if she will tell you so you can focus on one or the other. Just be there like a friend and don't try and push her into deeper feelings for you because right now she would be quite tempted to get back together before she is ready just because she doesn't want to be alone and because you are a sort of safety net for her right now.

Also be prepared that she may not come back when's she's better. She may stay friends but she may realize that she was with you for the wrong reasons and her love was not real love. This is not to say that she wont come back but its impossible to know one way or the other.