Gwyn, your post has brought tears to my eyes, and memories flooding back. My husband suddenly died...my goodness, it's been nearly 18 years now. It was so very, very hard at first. I didn't think I would survive, and most days, didn't want to. My daughters were both in high school and I had 3 foster babies to care for. That kept me going during the first months when I think I was in shock.(you are right, you think they have just gone out for awhile.) My advice would be to find a grief support group. It took me a couple years, and I think if I had reached out sooner it would have been better. I will pray for you, and be happy to listen if you want to send me an email or PM.
There is life ahead. There are some wonderful people on this board who will support you too.