Here’s another experiment you can do.
Imagine that you are only allowed to buy one gift for someone, and that is the only gift you are allowed to give this year. You put a lot of thought into it, and it is the focus of what you do. And when you have found the ideal gift your “mission” is accomplished and you feel tremendous satisfaction.
What does this have to do with eliminating overwhelm? Instead of a gift substitute a task you have to complete. It can be any task, from actually getting a present for someone to buying food for a holiday dinner. Keep in mind that it should also be something you can accomplish in a day versus something like “decorate the entire house”. That task will be the focus of your day, and all other tasks will be basically irrelevant. Like the gift, you’ll spend all your effort and energy on that task, and when you complete it you will feel a sense of accomplishment.
The overwhelm has been eliminated and you have succeeded in accomplishing something that before seemed impossible. And you can now repeat the exercise the next day and the day after that. Best of all, you’ve experienced your own flow.