That is definitely beyond the scope of advice other than contact a professional.
Does he show any signs of harming you and the kids? Does he resent you?
If you and your family feel like he might hurt you before he hurts himself it is time to leave while you can.
Online advice could be bad, but it could be a blessing.
He might need a medication adjustment and a hug?
I know that sometimes all I need is a little affection and the world gets nice and rosey again.
Thanks.