I dont even know HOW to study

Guys how do i even put all of this info in my brain? Im a bsc doing all the science courses rn (mbg 2040, bioch 2580 etc), and i dont even feel like im fully grasping the info. Ive been “studying” since last week and i feel like i still know nothing. Tbh, ive just been re-writing all the slides bc thats what ive been doing since like high school?!!? Clearly it isnt working 🥲Help!! What do i do? Any techniques? I need to understand or at least memorize😭😭😭