Honestly, self-care is the most important of all cares and writing practices. There are many forms of fatigue and it is important to learn to recognize them in yourself. If you are tried, take a hiatus. Take a break. How ever long you need. Trust me, readers can tell when the Author is losing it. They will be willing to wait.
Besides, the fact that you even think about your story, is writing. It is planning, and figuring out your characters better. You gotta live in them.
If I may rant, that's my biggest peeve as a reader. I hate when characters aren't people.
At least for me, they are people first. Then, secondly, they just happen to be expressed via words than a corporeal form, but always, PEOPLE first.
So, moral of the story, go make yourself some Chamomile tea and stare at the sky, and just take a break.