How old are you guys? I think she's just a stupid young girl thinking about no one but herself. Think about all the hell she put you through. You don't have to hang out with her and if she wants you back. Don't do it! She is just using you as a boytoy. Only focus yourself on your daughter. BE STRONG FOR HER AND NO ONE ELSE. She will make you happy!
I wish you all the best of luck in life and hopefuly you will find love again. BE STRONG!