Originally Posted by Rose Mosse
You're dealing with very low self-esteem (lower than ever because of the number of times you got suckered into thinking any of it was real). She's being honest with you that she doesn't have what it takes to be in a relationship. I think it's time to focus more on that relationship you have with yourself and repair your trust in yourself (that you won't screw yourself over again with bad decisions).
Whether or not she's seeking mental help is none of your business. You already know she needs help. Resist the urge to bandaid anyone. You have more repairing to do and healing to do with yourself than you realize. Until you can repair your sense of self and your self-esteem, you'll always get dragged over the coals. You'll always be vulnerable to personalities like this. You'll be vulnerable to strong emotions like hatred and resentment and before you know it, you'll hate yourself more than you already do now. So? Start moving in the other direction.
Acknowledge your mistakes, practice more love not hate. Love means engaging with your world in a way that respects others and practices utmost respect for yourself, above all.