I think it would help you get started with detaching.
One thing you should focus on is accepting this truth: You, alone, are responsible for your happiness. Not H, not kids, not dog, not cat. YOU.
If you can truly accept, and live by, this simple truth, your happiness is no longer dependant on your H's moods/comments/actions. Which makes it easier to let H's negative comments roll off your back. I would venture a guess that once he sees he is no longer getting to you with his negative comments, he will stop making them.
