Exercise makes a big difference for me. Running outside is where I find the biggest impact. Something about the repetitive motion, being in a different, constantly changing environment and time to myself helps me center myself, and helps even afterwards (usually a day or two.) I know running isn’t for everyone, but you might try some sort of exercise that you enjoy.
I also have a standing desk and recently got a cheap walking treadmill that can move under it or out of the way, and those sometimes help when I’m finding it impossible to focus. I realize the treadmill isn’t accessible to everyone, but I’ve literally made a standing desk out of boxes a couple times, if you want to just give it a try.
I know that neither of these are guaranteed, but might be worth a try to see if they help a bit. Good luck and I hope you find some things that help a bit.
Yes, I know what you mean! I often say that running is my meditation.