j4j, you need to go speak to counsellor, flashbacks etc it's post traumatic stress etc.
for now your only response is to tell him "you not coming back"
way down the line if he understands why you saying this then frank and open discussion with a third party - who knows...
when i said before take one month away - it was for you to have clear in your mind - dont even think about the future or second chances for at least one month. make a clear break no contact for one month at least. gives you time to talk thru.
DC if they want to see him - only strictly supervised ask SS help in arranging this .
however much he begs, pleads. second chances come after years....not days or weeks....
and the additional information you have given in your posts suggest far deeper longer term issues in your relationship that go way beyond a complete one off - especially your comments on how he rough handles the dc and you ahve to protect them from him. that signifies a far far deeper problem and significant risk and danger to your DC.
you need to get stronger in your mind and talk to somone in rl to go thru what happened over and over til you understand how wrong it all was. and talk about ho he deals with the DC. this is less about you and more about protecting the DC. youc an take on that role - or if not then others will have to.
in a month without him wihtout even discussing second chances and fogivenness....you will see clearer - and hopefully make the long term decisions you need to make.