I am so sorry, both for what you have been through and what you will go through in the future.
I have been there. It sucks. My sons were six and ten the night their father finished dinner, pushed back his plate, and announced "Supper was good, I'm leaving you!" (Never cooked that meal again, I can tell you.)
He did leave. He left my babies crying and begging him not to leave with not a tear on his part. I can also associate with the dis-connected attitude, it is self absorption. Nobody and nothing is important except him and what he wants. He is still that way, three marriages later.
I hate to tell you this but I will be VERY surprised if it doesn't turn out later that there is another woman. Very rarely does anyone decide after ten years (twelve in my case) that they are unhappy without someone pointing out to them how unhappy they are. My "best friend" turned out to be better friends with my ex than I was. One more reason I felt like a fool - my sister was out of town the night he announced he was leaving so I went to my best friend (her) and poured out my heart. He let me go and she cried with me.
Please, for your children's sake listen to everyone here and get a lawyer. Then do what she/he tells you to do. From now on it is your responsibility to stand up for your children. Can you really trust a someone who cares no more about their feelings than this man? Can you ever imagine hurting them like this? Well then, don't give him the chance to hurt them any more than he has.
Do NOT leave your home. It is your children's home too. I think your husband has a rude surprise waiting for him when the courts rule.
Get some counseling for your children and yourself. It is wonderfully cleansing to be able to tell someone the truth about how hurt and angry you are without having to hold back. I can look at my wonderful sons now and put my finger on the scars in their souls that their father put there. Thankfully there doesn't seem to be too much of him in their personalities. Both are happily married with sons of their own. I think they would cut off their arms before they hurt their little boys.
My heart hurts for you. Writing this has brought back feelings I haven't had for many years. You will get through this and you will be stronger for it. I'll feel better when you log on and post that you are mad at him. Getting mad is the first step toward healing.
PM me if I can help you in any way. Turn to the DIS when you need to vent. Build your support system of family and friends. You will learn that some people you thought were your friends are not and that some who you didn't know cared, do.
Penny