Scheduled creativity

Sometimes writing drives me nuts. When what I want to write or what I need to get finished doesn't match what comes out on the computer screen I could just go mad. Do other writers ever feel this way? I have days when I clear my schedule, the everyday tasks are all done, the house is quiet and I sit down to write...only to discover I can't think of a single thing to say. Then there are days when I am already juggling a bunch of responsibilities and inspiration hits like lightening. I find myself frantically searching for a pen or a moment to look at a keyboard so I can capture the ideas before they dissolve. The struggle to balance disciplined writing strategy and sparks of inspiration continues each day.