Narccisim, Love, and "Issues"

Hello this is my first post in a while so please be kind :sad2:

I have dated a girl on and off for the past year or two. She has had many childhood issues such as abandonment and neglect that have made her ice cold and into somewhat of a narcissist. She can not show gratitude, affection and she wonders if love really exists. However their have been moments of weakness where she lets down her walls and criess and tells me she doesn't want to be alone forever. She is my best friend and we also love each other in every sense of the word. We would do anything for each other. She says I am everything she wants in a guy but she can't be in a relationship with me right now. She says she needs to gain perspective on what we had and she needs to date someone else. She thanked me for helping her but says she just cant be with one person right now and she needs to explore. Obviously the thought of her with someone else kills me but she says she needs to. At the same time however she hints she doesn't want to leave me.

My question is: Do I wait for her to come around? Can I fix her problems and make her stay with me? Or is she unfortunately going to bounce from relationship to relationship forever because of these childhood issues?

Thank you!