People are motivated by importance.
When your boss asks you to get started on a big project, or your teacher tells you your final paper is due, knowing that it's important to them is enough to get the work done.
Unless you have ADHD.
Knowing that something is important simply isn't enough to provide the motivation required to get something done.
These tasks can feel impossible.
Instead, people with ADHD are primarily driven by interest and fascination.
To thrive in a world driven by importance, you must find other ways of motivation.
You have to become a pro at finding interest in the uninteresting, to manufacture fascination where none exists.
When hyperfocused, your level of production can shoot through the roof, so adding interesting work in order to make existing work more tolerable is one solution to turn to.
Find something interesting, package it with the boring, and get both done at the same time.
This won't be easy. But it will become easier.
You need to become an expert on your own behavior.
When you find something that works, write it down.
Every time you are able to find interest in the uninteresting, document your technique and add it to your list.
Eventually, you will begin to find patterns, and with patterns, strategies can emerge.