I don't completely know your situation but I would guess he will change his tune at some point and then you will have to remind yourself that you don't want yourself and your kids to go through this anymore. This could be a good thing for you.
You are going to hurt and be sad, but you will come out of it. It's like ending any relationship, except you have years of manipulation to add to it. I am still hurting and sad because I am also recently separated, but it is really one day at a time. You will go through a ton of emotions every day. Just keep pushing forward. Hugs to you.