I have severe ADHD too (hyperactivity), and I'm taking pills since I was a child (for nearly 13 years now). You have to find something you are passionnate about in your work, that way, you always manage to get it done. You also want to keep a clean space for your work, and organize stuff well so you don't end up looking for half of your stuff all the time. Allow yourself to have breaks, to relax and to take the edge off like going on your phone in another room, but get yourself back up to work again. Also, give yourself timeframes. Think about how proud of yourself you will be after you're done, no matther how much more effort you have to put in more than others, the result will pay off on the long-run. I believe in you !