Do you have too much to do? Then change that. Make your “To-Do” list only one item: “Make a list of the things I have to do.”
Then you still only have one item! The list!
It seems silly, but the power of queueing is really amazing. If you can catch a ball, then you could probably catch five balls in a row. But not if I threw all five at you at once. The power of the list is just that: it turns five things into one thing. It’s a wonderful defensive filter.
So when you’re feeling overwhelmed, just write it down. Watch it fall away.