Divorce is hard. Divorce with children is devastating. Do the best you can to be the adult. Be gracious. Forgive. Really move on with your life, for everyone involved.
Above all, no matter what they say or do to tear you down. Trust me they will try, don’t reciprocate if at all possible. Remember your identity is in Christ, and Christ alone. You are better than that.
This has been a public service announcement.