The only way you can heal, can surmount the pain, is when you take control. When you prove that the Ex no longer has any power over you, that he can not manipulate you.
You need to do this.
You can’t live your life feeling as if you were a victim.
If you don’t surmount it you will be that old woman babbling about her Ex as if it were last week he beat her or cheated when it was forty years ago.
Until you can reach that plateau of indifference you are still in a position of weakness. Once you surmount it, you feel whole. You get back ‘yourself’.
You don’t have a normal relationship for the sake of the kids or a smooth life, you do it to regain your soul. You do it so as to let go of all the hate and anger and pain, and turn that Ex into a minor character in your life.