stuck between reality and fantasy

Hello there,

So I was dating a man off and on over 3 years. We are not together. It was a dysfunctional and verbally abusive relationship (back and forth between good and not good). Things would be fine then suddenly I would get accused or attacked for things I wasn’t doing. and then punished for it. Anyway, my issue is that I catch myself going back and forth between the reality. (knowing that we are not together. It did not work. We tried many times. It was unhealthy. It’s better that he is not in my life (less drama, emotional rollercoaster,, hurt) I deserve better. It wasn’t my fault) TO fantasizing what could have been. The life we could have had. hopeful. Maybe it would be different the 100th time. My question is how do I keep from second-guessing myself and going back and forth between the two worlds (logic vs emotion)