I think everyone agrees that both parties need to forgive each other. One of the things that counselors sometimes do is to have each spouse write a letter to the other expressing sorrow for the things they have done to hurt the other in the marriage. A follow up to that is to have each spouse write a letter specifically forgiving the other.
Doing this in writing is so much more effective than speaking it because it forces you to choose your words more carefully, and because it provides a written record that can give lasting comfort.
I don't necessarily think this will work for you, GH, but I read it in some marriage book recently and thought it was generally a good idea.
The LORD is near to all who call on him, to all who call on him in truth." (Psalm 145:18)