You do not achieve goals by taking breaks here and there, chipping away when you feel like it. You achieve goals by consistently persisting forward and never taking a day off. Thirty minutes per day yields better results than three hours once per week. If you take a break, you will lose momentum. Lose momentum, and your passion project may fade to the back of your mind. You will lose.
If your mission is tied to your very core, then maybe you can survive output droughts. To intertwine your mission to your core in the first place, you need to consistently believe in it. There are feature films I have wanted to produce since I was eleven years old. I have no polished screenplays or financing to show for them, no plans to produce anytime soon. I touch these projects once every few months at best. But I wake up at night after dreaming about them every so often. They will not leave me alone. To make the films, however, I need to commit. I will need to start making daily progress to finish them. They will never get made otherwise.