It’ll happen. Despair and work from the depths of your being go hand-in-hand. From time-to-time. What can you do?
The stark option is to quit, stop working. Do something else with your free time. It’s an easier way, at least at first. The itch will be there at the back of your consciousness unless you channel it into another pursuit of making things.
The obvious answer someone with a blog writing about creation and art will say is that you have to keep working. It’s obvious because the idea surrounds us, culturally. I’m a big fan of “JUST DO IT™” as it applies to life in general, don’t get me wrong. But try something else.
Not forever. Just for now. Look at everything you’ve done, and everything you want to do outside your routine. Breathe deeply, steadily. Try to imagine you aren’t attached to any outcome. Remember that you’re just doing the work and the process is your discipline. Discipline has its own benefits, creation has its own benefits, regardless of how bad it is, or how wonderful it is.
Then start working again. Just do it.