I have anxiety day dreams. I have had them pretty much since my children have been born. They increased dramatically in frequency, intensity and lunacy when my grandchildren were born.
The dreams would appear suddenly, without provocation or prompting at any time of the day. They would appear any place. There was no rationale for them other, as nearly as I could tell, than the fact that I loved the children more than my frail human heart could stand. The dreams were a perverse way of punishing myself. That, at least, was my observation.
My wife taught me a technique for disabling, disbanding and banishing those horrible dreams. "Just think of 5 beautiful things around you right now. And name them."
The sun. The mountains. A bird's song. Green grass. A wild turkey.
Her trick almost always works and I can use it to keep those dreams away. Now, I can almost always fight them away before they even start. I don't name them. I don't think about them. And I won't write anymore about them!