I am so sorry. What are you meant to do? Whatever it takes for you, and your family, to get through this.
Sometimes you may want to talk about him. Other times that will be the last thing you can bear to do. Sometimes you will be numb, some angry, sometimes crying, sometimes almost feeling guilty just for being alive. All that is normal of you. And if you ever want to talk about him, there is always someone on here.
I guess at the minute one of the really bad bits is having to tell your children in the morning. How old are they? Did they know he was ill? If they're young children, I'm told it's really important to avoid euphemisms like sleeping, because it can be confusing, or make them afraid to sleep.
Try to keep having sips of fluid, and a nibble of something, even though you don't want to. It helps your body cope a bit better with sleep being impossible.
But mainly, I just wish I could give you a hug.