There's a really short answer to this one. You're better off without her! You've managed to escape, don't throw yourself back into her clutches. It's natural to be sad when a friendship ends but you are clearly not the guilty party here.
You obviously have the patience of a saint even to have put up with this girl. She didn't appreciate you then, and she's not going to now. She displayed qualities of a self involved narcissist, she didn't value your friendship and used you as an audience. You were probably a valuable sounding board and good for her ego.
If she hasn't tried to reach out to you since then, I'd say leave well enough alone and don't get back into a bad situation, she's not worth it.
Friendship is about give and take, not take, take, take!
Do you agree with Assumpta's advice? Let us know how you would deal with this situation.