If it's happening because of a lowered or nonexistent ability to prioritize, that isn't procrastination, because it is not deliberate.
This is where Autistics can get into trouble, not being able to put down something they're in the middle of to take care of more time sensitive matters. We end up being called procrastinators because of this, and even convince ourselves that we are procrastinators. ADDer's are prone to the same thing. Imagine having both. I do, and it SUCKS.
The only way I have found to deal with it that works is to study prioritizing strategies, and OBSESS over them to the point that they drive what you do. The hardest part of adjusting to priorities though, is forcing yourself to put one thing down to start something else, or picking up where you left off with a previous unfinished task. The best way I've found to deal with that problem if find ways to "leave tracks" (notes of anything you think you'll most easily forget) or find ways of identifying the best stages at which to leave a project so that it can be easily picked up and continued without too much thought.
It ain't easy! And I suck at it. I suck so bad at it that I haven't even had a planning book going for a few years now.
I have gone through periods of keeping scheduling books, task and priority lists. When I do use them, it works very well and a get a LOT done. But I DO have to obsess over the organizational process, else it falls to the wayside and the usual chaos eventually ensues.
Obsessing over overcoming this problem......I wonder if that would help. Could be a possibility.