As you are well aware, physical clutter can be distracting, frustrating, and lead to overwhelm. However your own thoughts can have the same effect.
Take a minute to identify all the little things that have been “nagging you” or keeping you up at night. Write them down, thoughts, tasks, errands, plans, and allocate ten minutes to work on the list. I find that I spend more energy worrying about whether I will remember to do something, reminding myself to do it, rewriting it on my to do list everyday, than the energy it would take to simply spend five minutes writing the email, or making the phone call, or writing a thank you note.
Then cross if off your list and enjoy a moment of accomplishment and less mental clutter!
Be well and take excellent care of yourself!