Would it help you detach if you knew that detaching is something that's important to do even in healthy marriages? In fact, some therapists feel that becoming emotionally enmeshed in your partner and needing to learn how to break free is a normal stage of marriage.
In other words, don't frame it as, I have to learn to detach because my wife left me. Frame it as, I have to learn to be emotionally self-sufficient because that's a critical skill to have if I want a healthy relationship.
My husband told me a couple of weeks ago that he loves me and is happy we're married. I am still working on detaching, because it is so easy to fallback into old, enmeshed habits. But since I want our new, healthier relationship, I keep working on detaching.
Detaching is for life.
Me: 44 H: 44 Kids: 20, 16, 16, and 10 Together/Married: 22 years H announced he was emotionally detached and considering D: 4/4/16 H announced he is going to try to stay and reconnect: 5/1/16