HI seven seven,
I'm sorry that you are having such a hard time moving on from this. I can understand. It's very painful. Forgiveness is the only way to move forward if you want to continue the relationship. Forgiveness is a choice. It doesn't mean that what the person did is forgotten or that things even have to go back to the way they were, but it does mean that this situation will not continue to control you.
One way you could help move forward is to look at mindfulness. This is being present in the moment, not in the past and not in the future. Our workshop
Triggering, Mindfulness, and WiseMind might help you with this.