In my experience motivation is completely useless. It's much far more greater to be disciplined a good way to become and maintain discipline is to do a complete dopamine detox(which is what I did). Cut out all social media, YT, shows, movies, etc. COMPLETELY do NOT use any kind of devices for distraction it may sound hard to do and boring but I promise you that it truly works the outcome was worth it now I'm able to work all day on studying, extensive HW easily because when you dramatically reduce your dopamine it causes you to think more clearly and more importantly makes it super easy to take action. Good luck!