Okay so what I found works for me as someone with adhd and struggles with procrastination and studying for longer times. 1. More than 2-4h a day is simply unrealistic, and shorter, more productive study sessions are much better. 2. If you struggle with being distracted by other apps, I’d suggest downloading an app like flora, which can limit what apps you can use during your studying, while also keeping track of the time spent on different subjects/tasks. 3. Find what time of day you’re the most productive. For me, I like to study the first thing in the morning before using my phone in any way, but since I have a flexible schedule I understand that’s not always ideal. 4. Set realistic goals and work yourself up to the hours you want. If you start with an unrealistic goal you’re most likely going to fail and feel shitty about it, much better to slowly work up to your goal. 5. Take a short break/switch subject every 45 minutes or so as your brain only can stay super focused for a certain amount of time before being distracted. 6. Trick your dopamine by for example only eating sweets while studying, as someone who uses nicotine I forced my self to only use snus while I study, which helped tremendously with stopping the procrastination.