Luciddreaming – I believe these awful dreams arise out of the culture we grew up in – a culture that sees death as the end of all. We see it on all sides. Even if we believe in survival of those we love the negative influence of the scientific opinion, based on the ancient belief that the atom is the basis of us, and consciousness arises out some obscure brain process, and as atoms are physical, we are completely wiped out at death.
That is not so, and I state it not as an article of faith or belief but from experience. It is good to read the book Closer to the Light, as it can be a great experience.
So I see your dreams as a replaying of the awful feeling that death, and the experience of death is awful. Most people are taught fear of death - not by directly telling us, but by our attitudes and responses, especially the grief that most people experience at the death of someone they love. All of that is telling us how awful death is.
But of course my saying all that doesn’t rob you of your fear that creates such awful pictures of death. But maybe the book I recommended with help you toward a different view of it.
When your husband died he did come back to you. He is with you every time you feel love for him.
Tony