Let your relationship transform. Burn the old and see what emerges.
If your relationship is going to have any chance at re-emerging in a new, healthy form that allows you to be friends and strong parenting partners, you have to let it all go first. Who knows what you’ll keep or who you will become. Don’t feel betrayed if the other person withdraws or remains silent when you start a riff on how hard it is to blah blah blah. She/he is wisely trying to build new boundaries for the care and safety of your relationship. It may feel lousy and lonely for a while but it’s the only way to move forward in a healthy way.