What ever you do, do not rush into action; this is no time for rash behavior, or for being a victim. Did you answer her question about getting married? Are you guilty of infidelity or emotional callousness? Sounds like there is something going on below the surface that you are unaware of. You need Aphrodite’s help and I hope you will ask her for it.
If you can take a six month break from your relationship - please consider it. Only time can heal this wound and give you the proper perspective. This is the kind of situation that requires therapy and I recommend you get individual therapy first, and after you are able to rationally discuss what happened, get couples therapy if a reunion seems possible.
My advice is: do not beg or cry in front of her, do not threaten or try to bribe her back, or make unrealistic promises in an attempt to keep her. Indifference may work better than any of these tactics. Relationships are like water they flow to their own level, if one is patient with fate. Love that is meant to be finds a way, while relationships that have served their purpose move on, change and evolve.
Even though you are now separated, it doesn’t mean you will lose her. Some of my best friends are ex lovers. The important thing is that you do not wound yourself more in your grieving process. Remember some of Aphrodite’s best gifts are unanswered prayers.
Who knows what your future destiny with her is? All we know about her position is that she still loves you but doesn't want to live with you at this time. One day you may thank your lucky stars that your life changed in ways you were not prepared for. In the meantime, nurture yourself, take care of your self, love your self and be yourself as much as possible. Your own happiness is the best cure.
I wish you both the best,