Your child is the most important person in the world to you. Despite that, the person you hate the most is the only other person who loves your child as much as you do. You have a divorce, but that doesn't mean you get to walk away from the person you despise.
To you, your ex is toxic, but to your child, he's the epitome of everything a good father should be. You can't justify trying to remove him from your child's life, even though you can't stand to be around him. What can you do to make this easier on yourself?