Write to think. Don’t try to know where you’re going before you start writing, but write to find out what you think, or find the story you need to tell. Never expect that a particular time-unit of writing will produce a given number of publishable words. You must learn to think of your writing time as a period of discovery, in which you find out what you think, or what images and rhythms tend to emerge from your mind, or where a story seems to want to go. If you focus on discovery, then something worth sharing with others will emerge, in its own way and on its own schedule. But that’s not the kind of thing that can be forced. Allow yourself the freedom to explore.