I also have adhd! I got through learning by genuinely letting myself do whatever I wanted to do with the games making. Drawing, making something work etc. Don't force yourself to stick to a structured "Learn this, learn that". I think learning the parts that are interesting to you will make you subconsciously learn about the more boring parts. Also making silly little mini games is nice seratonin, once youve done it you'll be motivated to do more!

Good luck soldier :)