I got the ADHD too, I know the struggle. Here's the thing, it can be a superpower IF you learn how to work with it. Everyone who deals with ADHD has their own unique struggle, so my method might not work well for you. But what I like to do is keep my writing synchronized with my natural motivation cycles. There's nothing wrong with writing the specific parts you feel the most passionate about first, then going back and filling in the rest of the details later. Or you can start with an outline then flesh out the story from there. You can also tackle it bit-by-bit. Maybe only doing 100-200 words in a day, slowly chipping away until you find that big break where you can use your hyperfocus and get a few thousand words done. Try to find ways to work WITH the ADHD instead of fighting it.