All you need to do is continue to work on yourself and your self confidence. The worst thing you can do is appear NEEDY to him which from the sounds of your posts is how you are coming off. Dont act depressed or sad. Dont try to manipulate him with GUILT. Stop doing what doesnt work. Remember "cheeseless tunnels"...
Why can't he watch the kids while you go work out or take a dance class. Show him you are moving on with your life and you will MOST LIKELY see a change in him. He will feel like he's loosing YOU. He will feel like he has LOST CONTROL. That is what YOU felt remember. Switch the roles around on him and his head will spin.
That in my opinion from the hundreds of stories I've read on here is the ONLY way you could have a HEALTHY R with him.