Sorry to hear of your struggles. I am sometimes similar. One thing that has helped me on occasion was writing a very rough outline that serves as a plan. Underneath the outline I’ll put random bits of information I might want somewhere, usually not even complete sentences but as bullets. Then I’ll sort those bullets and copy and paste them into the outline wherever they’d most logically fit. Finally I turn the bullets into proper sentences and add transitions to make these flow before proofreading. This process has sometimes helped me get “unstuck” because I can get information out of my head without it being perfect and organized from the beginning. I basically dump my bazillion random chaotic thoughts out, then deal with converting them into proper writing later. It’s hard because our brains have many neurons firing and many thoughts occurring all at once, but sentences can only be written and read one word at a time. We’re forced to turn parallel processing into serial processing.

Another technique that I’ve rarely used but DON’T recommend for obvious reasons comes from a bumper sticker I saw: “Write drunk, edit sober.”

Best of luck to you!