Dr. Kubler-Ross wrote a fantastic book called On Death and Dying. There are several stages people go through when they find out they are dying. It's no surprise that when a loved one dies, particularly a life partner, the ones left behind experience similar stages.
I was in shock from the moment I realized Rich was gone to the time my emotional novocain wore off. It was as if I was watching someone else being me. I have to say that in the beginning it was a Godsend! I never would have been able to do all the necessary things I needed to do if I hadn't been numb.
Here's a pretty good article that explains the stages of grief.
Inner Sanctity