You know, I've been told to leave, and I've told women to leave. Yeah its hard, and yeah it hurts, nobody here will say it isn't.
Best way to do this is walk away, don't call her to tell her you are walking away. Just do it cold turkey, anything else just prolongs the pain.
Now if in a month or two she calls you, just tell her she wanted space and you are giving it. Put it on her shoulders. In the mean time you move on with your life and find a woman that knows what she wants... trust me, its usually the woman that knows and the guy that doesn't.
You have to simply pick up yourself up, and from this moment on pretend she no longer exists. No calls, no emails, to text messages, just stop and move on.
In a few months when you find a woman that knows what she wants in life you will be thanking us, and come to the realization of what a waste of your life this one has been.
Relationships take two people... if one isn't doing their part, or doesn't want to, or even decides there is no relationship then you have to move on.
She has made it clear to the rest of us there is nothing... there never will be anything and any belief to the contrary is delusional behavior.
And you ARE being delusional, and you ARE blind to the signals she is giving that are obvious to everyone else here.
You can't make anyone else do or think what you want... so its stupid to try or even think you can. You will end up in a straight jacket in a padded cell before that ever works.
Now do you want to end up in a nut house or are you going to take charge of your life and move on?