Not your job to make him understand
In the last few years I've become more a parent than a lover, responding to my wife's more and more child like behavior. I hate this behavior.
I finally realized that by accepting this role, I reinforce her actions. I've stopped doing so many things that a parent does for a 10 year old, I've told her I'm not her father, not her white knight, that love requires giving as well as receiving, marriage needs adults.
You don't have to make your H understand anything, all you have to do is file for divorce. I don't know where you live, but since you are young, with young children and have relied on your parents' help, you may not have much in the way of assets. This means in many states you have little to lose by doing a do-it-yourself divorce. Start by googling
You will find a lot of information. Move out and get a restraining order, call a local women's shelter, in CT and some other states dialing 211 will connect you to someone who can guide you.
You have clearly become a woman, I know the path is hard, but you can do it, you'll look back and wonder what you feared, you will not see dragons. Your kids will thank you in time.
Good luck, feel free to post again or mail back channel.