Oh - stay away from the crazy. Honestly.

Sure, you're sorry she feels bad and her fantasy life isn't working out and she realizes she messed up by leaving a good guy behind - fine. But do not let yourself get pulled back into anything with someone that unstable and let's face it, selfish. The things she said to you are pretty unforgiveable. And she doesn't sound like she's come to some mature understanding and acceptance of what she did wrong - she's just looking for someone to ease her pain and right now she thinks that might be you.

Don't get sucked in.