Studying for excessive amounts of time at a stretch have diminishing returns for nuerotypical people too, so trying to cram 10 hours a day in tends to be counterproductive for anyone.
Before I was diagnosed in my 30s, my successful uneducated approach was bursts of studying with short and frequent breaks where I would note down the distracting things for later so I could get them out of my mind and refocus. Don't remember where I heard the suggestion from, but it worked fairly well. So I would focus for an hour or so until I noticed I was off track, write down the non-related stuff, then pick back up where I was.
It didn't work for things I had no interest in, but it did work well for times when I was getting distracted. Keep in mind that I did not have any idea that I was ADHD at the time, this was a study tip from someone I knew.
Now that I am on medication I still do the same thing and it is even more effective, although with meds it even works when doing things I have no interest in. Regular short breaks to clear the mind help both when the meds are working and when they have worn off. Can't be too long or I move on to something else.
Overall I guess my recommendation is that you don't overdo the time per day because it will become counterproductive at some point, but do take regular short breaks to see if you are able to refocus and continue.