When I was a student, I used to sart studying on waking up, study all day then go to bed dreaming about maths. Not everyone can study like me, but there are some techniques you can use to keep getting better at studying
Always have several unsolved questions to be solved - today, tomorrow, next week... Your mind is a subconscious calculator, churing away at it;s own slow and relentless speed. One day you may turn a corner and see some answers.
Cycle, walk or run. These activities teach you persistence and fill you brain with thought giving oxygen. Even fat people can walk or cycle and don;t make excuses - no fat man ever squashed his bike flat, or compresed his legs to zero length.
Use several textbooks, each one with and index. An explanation in one book may illuminate something that reads like garbage in another book
Use the internet sparingly to look things up. Looking up something does not mean you will understand it. Understanding something mean reflecting on it, twisting and turning it in your mind. Often this happens away from your phone or PC, looking up at the sky
Be aware of every deadline and prepare for it early.
Make your own notes. I like to have students fill blank pages at the front and back of textbooks with brief and punchy sentences or diagrams to summarise a topic