Grading is dispiriting at the best of times. There is too much of it to do to a very tight deadline. And despite the occasional brilliant paper or clear demonstration that students are getting it, there are too many opportunities to doubt your own performance as a teacher.
Are you further punishing yourself by telling yourself you can’t do any of your own writing and research until you’ve finished the grading?
If so, stop it.
Writing is the foundation of everything you do
Writing is not selfish. Writing is how you process ideas and make them intelligible to yourself and others. Your teaching, your graduate supervision, and everything else is built on your deep interest in the topics you write about and the deep knowledge you have acquired in order to write about them in a scholarly way.
I know you are busy. It feels like you don’t have time to write. I would suggest you don’t have time not to write. Writing will energize you.
Make writing a priority, even now
To make something a priority does not mean that you will spend more time on it than anything else. It means that it is most important. It means that you will allocate resources (of time, energy, etc) to it before you allocate resources to other things.
What happens if you write first? Before you start grading. Every day. How would that change how grading feels?
Try writing first thing in the morning every day. Right after breakfast, with your coffee/tea. Maybe you can only find 15 minutes for writing. Maybe you need to get up 15-30 minutes earlier just to find that 15 minutes. That’s okay. It’s enough.
See what difference it makes to how you feel.
If you aren’t sure about the 15 minute thing, there is more information, and a downloadable tracking sheet, here.