The idea is you want to do exactly the opposite of what she expects. Stop fighting her. Give her space. The more you try to convince her that you love her, she's making a mistake and you want her to stay, the more she'll resist and insist that she's making the right decision. You'll drive her further away. You want to do what will bring her back. Try using this rule of thumb..."is what i am about to do right now going to make me more attractive to her or push her away?" I had a DB coach session and this is what she told me.
Try taking a step back and get some perspective. I know it feels desperate right now, but she is still engaged with you. You need to give her space if she is going to come around. Unfortunately that takes time.