I wrote my W a letter last week. This is what I wrote:
I take responsibility for what has happened. I should have been more attentive and listened to what you were saying. I know it's too late but wanted you to know that I'm sorry and hope you can forgive me someday.
She replied with an email:
I got your letter. Thank you. I do forgive you. I truly hope that you find a way to not feel angry and enjoy life.
I didn't want to hurt you, but it is impossible to separate without causing pain. I hope that you can forgive me one day too.