a period of poor luck
Their marriage has hit a bad patch.
Giving up the bad patch as hopeless, I would go on and, after I had left it behind, discover the dynamite capable of blasting it.
It was just a bad patch, the kind of thing that happens when people who love each other stop paying attention for a few years.
A period of difficulty, suffering, etc: You went through a real bad patch, a shaky time (1920s+ British)