Not unless H decides for himself that he needs to change, and does something about it .
And if he doesn't get help, things could get worse. It feels as if he is taking out his own unhappiness on you and the DS's. Horrible for you, and the problem for HIM is that it isn't even an effective way to deal with his unhappiness or make things better. He is still unhappy however badly he treats you and DS. So then he will blame you for not making him happier, and it will be a tightening viscious circle.
There's no need to do anything rash, one step at a time is fine, see a solicitor (if you can find the money - or is there a cheap / free way to establish your rights, I wonder?), and think things through step by step, and how you can get the right support.
I don't think I would talk to H about it - it will just cause friction that adds to your considerable burden. He has had two reminders / prompts to seek help, what more can you do? Just wait and see if he takes the initiative, while quietly building strength around your OPTIONS.