There’s a certain amount of rhythm a writer tries to maintain while composing his latest masterpiece. Much creative writing starts out as a kind of stream of consciousness setting down of thoughts on paper, and then, eventually, those thoughts become a single coherent stream. And from that stream rolls in the creative tide.
The frustrating part is when that flow is difficult to achieve. Whether one calls it writer’s block or simple tiredness from long hours at a day job, knowing what you want to say but not being able to set it down the way you want—not being able to achieve a “rhythm”—is aggravating.
Nevertheless, the rhythm eventually comes, and the flow follows, and the tide rolls in.
Roll with it.