I would get therapy....for YOURSELF. He needs to go alone; you can contact the Domestic Violence hotline.
You cannot help him.

The Verbally Abusive Relationship by Patricia Evans saved my life. He is using emotional blackmail re the killing himself. Look at the Domestic Wheel of Violence: http://www.domesticviolence.org/violence-wheel/

This is waaaay too much to deal with; leaving and protecting your children is the best you can do; trust me you may not think they know what is going on, but they do....dependidng on their age.

Again, you need to realize you can NOT help him.