question for senior nursing students and RN's

I'm a first-year student, and I'm at the end of my first semester, barely hanging on. I'm very disappointed in my grades, and honestly, it's challenging for me to grasp topics, especially AnaPhy. I spend a lot of time rewriting and reviewing a specific topic to the point where I can't really understand anything I'm reading. This occupies the majority of my time, preventing me from reviewing other topics in this subject and other subjects.

Do you have any tips on how to study? I easily get drained, and after 3 to 4 hours of studying, nothing really clicks in my head anymore. I get so upset when this happens, leading me to pull all-nighters, but in the end, I still get very low scores. I don't want to keep doing this and still be in the same situation this upcoming second semester. I would really appreciate advice.