So sorry for the ordeal you are going through right now. Please vent as much as you want, don't keep your frustration and anger inside, also it might help you to sort out a few things.
I totally understand your need to express your pain and sorrow.
Do you really think in case of a divorce, he would like to have 50% of custody and he can handle 3 kids on his own during a few days in a row without any help?
When he was talking about wanting a divorce, what was his position in regard of the children?
Me 52+ WH 57+ Married 20 + Piecing since 2016 (ready to give up...)