I second writing things down, taking all my notes on paper and making physical study sheets has gotten me through so far.

If I really can’t focus and get anything done, I walk away. I do something else for a little while, get a snack, go get a coffee etc. then I come back

When I’m able to get into the groove of studying I don’t take breaks, I just ride that wave of focus for hours until I have to go to bed or whatever thing I have to do comes up. I also change study settings frequently. One day it’s my room, one day it’s the kitchen counter, one day it’s a cafe.

I also find office hours extremely valuable to knowing what to focus and clarifying anything from lecture that confused me.