Penney,
My thoughts and prayers are with you. Also, I would like to echo the earlier posts encouraging you to seek grief counseling. It has been said over and over again that there is no greater pain than losing a child - and this apparently just happened so first of all, give yourself some time. Also, know that your spouse/kids are really hurting, too...cry with them, laugh with them, cry with them some more.
As for you going back to work ... I know you don't want to, but sometimes getting back into the swing of life helps. It sounds like this just happened and I am sure that the people you work with would understand if you had to just walk away, or if you broke out in tears, or whatever.
Best of luck to you and your family, Penney...and know that our prayers are with you!