Call it quits. But make sure you do it carefully as he could be dangerously abusive and don't be swayed by his threats to hurt or kill himself, which may be verbal or made through his actions, like not wearing a seatbelt or helmet.
You're drowning under the weight of his world, immaturity, bad history and abuse. It's also obvious to us, the peanut gallery, that he doesn't value his life, your life or his children's lives.
Call it quits.