How to move on

I recently ended a relationship with the person I love and am having a hard time “moving on” as in I am attached to him emotionally. I want to be but that is not the reality of things, so it is better for me to detach and move on.

One thing I think that is preventing me from moving on is all the negative feelings I had about what happened during our relationship. I imagine that if I fully let myself feel all the feelings that I will process them fully and then I will let go of them.

But this has me getting stuck in fighting with reality! Like, I am angry because this “shouldn’t have happened.” Now, I know that things happened exactly as they should have because they did but I did not want them to happen that way, and that is my truth and a thought I like my reasons for. So when I look at things that way, going back into the past doesn’t seem helpful to moving on and letting go because I’m thinking about him and how I wanted him to act.

What is better for moving on? Understanding the past through processing feelings or letting the feelings (and thoughts) go?