There is one thing that you need to accomplish today and if you do not do so you will feel guilty and perhaps a little depressed.
Odds are, it's the same thing you didn't do yesterday or the day before. That's one reason why so much stress and shame accompanies the uncompleted task.
Now you may say, "Wait there isn't just one thing! I have a whole list of uncompleted tasks."
Pick one that's important. Complete it today. Do nothing else until that chore is done.
Once it is finished, pick one more high priority and continue the process.
No multitasking. No pretending to make progress on a wide front. Just simple focus on one task until it is over.
Obvious? Sure. But also rare.