Well I have adhd too
So some of my levels I built and finished before my motivation ended, but not all of them
And something I've learned is that... you can teach yourself to build even without the motivation or hyperfocus. If you have a lot of the level finished, that is
Like one time I made 2 parts of my level NanaTech, but then got a PC problem for 6 months that made Geometry Dash unable to be opened
I had lost all my motivation by time the problem got fixed, but I just thought... it would suck for these 2 parts to go to waste. And that thought helped me finish the rest of the level
Point is, you can learn to build through demotivation