An exercise in awareness: notice the stuff around you and narrate it to yourself like you’re Thane Krios.
"a snow is falling, the road looks brighter already"
"a man walking down the street, talking on a phone, smiling"
"a young pair passes nearby; what do you want for dinner?, a man asks"
"a woman waiting for the bus, nervously glancing at her watch - perhaps the snowfall caused delays, or maybe she was cutting it short to begin with"
and so on
Might help to stop thinking about your own stuff all the time.
The important thing is to not try. At all. Just stop. Your ambitions, expectations, grand vision, your “ok this one is important so I need to do it right” - throw them out of the window, or flush down the toilet. Do stuff, I don’t know, just for the heck of it. Humor yourself. Plan some spectacular failure. Or be mediocre and do mediocre stuff. Everyone else is trying to be special - where’s the fun in that? Shameless mediocrity is better. Practice it. Celebrate it.
And then, after you do it for some time, you may start to notice that this thing you’re doing is not so bad after all. And all those little details you are so fond of are making it there anyway, but don’t make you an obsessive wreck for a change.
But don’t think about that for too long, or they’ll be back - crippling perfectionism, crushing weight of expectations, restless feeling of moving too slow, perpetual dissatisfaction with results - they’ll all be back and punch you and beat you and crush you again until you are lying on the floor unable to do a simple thing.
Just keep doing bland and mediocre stuff instead.