I have terrible ADHD, like really really bad.. I waited forever to go in and actually go through the testing and get diagnosed. Before that though, I had to do tons of studying for my bachelors degree, and eventually doctor. Finally, after having finished all my years of schooling, I actually got medicated for ADHD. I was too studbborn to be put on anything, but now I realize I basically made life so much harder then it needed to be, but I also did a SHITLOAD of studying with untreated ADHD.
It's all about finding what settings and techniques work for you personally. Eveyone is different. For me - I can't study with other peoiple, it's way too distracting and I don't end up learning anything. My best studying was done early in the day. I liked studying at coffee shops because of all of the noise and energy. I needed to rotate studying spots every couple hours. For certain subjects, working problems was way more beneficial then just reading and reading. Etc etc etc.
You will need to try different things, and find what works the best for you. Have faith Sherbrother.