I have two ideas.
The first is that the busier and more overwhelmed you feel and more stressed you are the more important it is to take a break. It just feels natural to try to get more work done. “Have to work harder. Have to work faster. Must get all of this work done! It’s piling up! I’m going crazy!” I say take a break. Just stop. You’re not being effective. Go somewhere and relax. Let your brain cool down and maybe even have a new idea or interesting thought while it’s at it. Then come back to work with a more level head and healthy state of mind and effectively complete your work. And who knows, maybe you’ll find that a lot of that worked that seemed important before really isn’t that important.
Which leads to the second idea. I bet there’s a large percentage of work that everyone does every day that just doesn’t need to be done. Work that will just naturally resolve itself without any intervention. You know the kind. Someone asks for something and then five or ten minutes later they say, “Never mind, I found it.” How much less work would you have if you just ignored people asking you for stuff and your less important tasks for a day to see if they resolve themselves? There’s a fine line to carefully tread between prudence and negligence, but I suspect there’s a not insignificant amount of time to be saved by just not doing stuff right away. Just keep an eye out for it.
So stop working and go relax when it feels like you have too much to do and should be working harder. Maybe you’ll come back with less to do and a smarter way of doing what you need to do. And with that said, I should disclaim that while the first idea is something I actively practice, the second idea is still baking in the oven, and I haven’t tried it much.