I'm so sorry you are having to go through this. It sound horendous. He needs to see someone, either a psychiatrist or therapist to help him through this grief and fear he is going through. When my mom died I though the whole world died, I really thought I would cease to exist without her. I didn't of course and have mostly come to terms with it now. But you do need to take care of yourself and do what you need to do, to do that.