I'm sorry that this has happened to you. You must be feeling so sad to lose a relationship that you thought was going to be for forever.
It's hard because you want comfort and closure from the person who hurt you. And this is the person you have always gone to for comfort...but you can't now.
I have begged ex boyfriends for the "truth," for closure, and even for another chance. I have met with them, explained my thoughts and feelings and have asked them to help me understand the reasons for the break up and to tell me the truth about other women....and, though, they might have listened to me, they didn't really care. It was over for them.
I left the "meetings" feeling so low and vulnerable, and no closer to the truth or to closure. It was like I gave them the last bit of power I had.
Now I keep that power for myself. I don't go to exes for comfort if they are the ones who have hurt me....even though it is such a strong impulse since that's what we do in our relationships...but the relationship is over.
I'm sorry, but I don't think any good can come of meeting with her. Sometimes we have to give ourselves our own closure.
I say the following gently: She's not with you. It's over. What more do you need?
Keep your dignity and don't see her. You already know enough.
Big hug to you.