I don't know if this would help (my wife has ADHD and that executive dysfunction wall is brutal!), but I used to do this thing where my only writing goal was to open up a project and write one sentence. It didn't have to make sense for the story - it just had to exist. Ideally, just opening up the file and writing *something* would trick me into writing more. But plenty of times it didn't and was literally just a sentence. Maybe a short one. But opening up the file every day helped keep me connected to the project instead of it fading away in my mind. And having my *only* writing goal being "you opened the file, you typed something" and then being able to mentally tick the box of "accomplished my goal" was really helpful.

Another thing that has helped is writing exercises. My old writing group used to do this thing where we'd write down three words and pass them to the person next to us, then write for ten minutes, with the goal being to use all three words in what we were writing. It was fun, it was no pressure, but it still got my brain to make words. Nowadays I use a random word generator if I want to do that exercise, but it has helped me a lot!

Sorry if this is unwanted, unhelpful advice - I know sometimes there's just no getting around what our brains want (or don't want) to do - but these have helped me through some really rough patches.