What has been her reaction to your entreaties?
Is she receptive to marriage counseling? Are you? If you both are, then seeing a licensed marriage counselor would be your best plan for attempting to repair your marriage. It can take a lot of work on both sides, but it offers the best hope of reconciliation.
Please let me know if you have further questions.
If she is unwilling to go to counseling in a last attempt to save the marriage, I doubt there is anything you can do or say to her that would change her mind. If you maintain a steady, pleasant demeanor through the next few months and into the future, she may change her mind. However, right now it appears she wants her freedom.
Sometimes people do marry for the second time after realizing their first partner was ideal for them after all. I'm sure you are broken-hearted over all of this. Having a marriage break up is one of the saddest things a couple can go through. I'm so sorry you are going through this,
All the best,
The same to you.