Quick! Grab a pen and paper. Write down the first task you know you “should” be doing. Write down the next task. Keep writing until you run out of tasks you feel you should be doing. Take a breather.
Somewhere in that list is the one unresolved item that’s taking up too much of your mental RAM. (Hint: It’s probably one of the first five things, or first three, or the very first, depending on how little (over-)thought you put into what you wrote.) Knock that out and everything else will go so much smoother today.
You’ll feel so better for doing that one task, too.
Don’t know how to do it? Start another list: Write down the second-to-last task that would have to be done before you could complete that other, pernicious task. If it’s “Do the dishes,” for example, start with “Dry off the clean dishes.” Keep working backwards: “Wash each dish,” “Find more dish soap,” “Empty out the sink,” “Grab the dishes in my room,” “Go to my room,” “Put this phone in my pocket.” Go into as much detail as you have to until you have something you can do right away.
Robots must always be told exactly what to do. Sometimes people need to be told that, too. You can be that person, at least for today.