You don't have a choice about whether she sees other men or not. That is her choice. You don't control that. You only control you.
Do you want to try to control her and get angry with her lack of commitment and decisions? Or do you want to validate her autonomy and showcase your 180s?
Do you want to get into a rebound relationship for comfort and in an attempt to manipulate her? Or do you want to demonstrate the character and commitment you are looking for in her?
Do you want to be impatient, demanding more that what she's willing to give, and upset with her for not doing more? Or do you want to be detached, grow to love yourself and the life you've been given, appreciative of your chance to grow, empathetic to her pain and confliction, and supportive of the decisions she must make to take care of herself?
Those are your choices. Which man do you want to be? Which gives you the best chance if reconciliation, and the best chance if future happiness should that not be in the cards? No one said this is easy. You fell short in the R. You get to stay on the same road or course correct.
Wishing you strength!
Me:38 XW:38 T:11 years M:8 years Kids: S14, D11, D7 BD/Move out day: 6/17/14, D final Dec 15