Hey, I'm a 5th year medical student and I've spent 20+ years revising now. I'd recommend you use active learning methods to revise as they help to increase productivity and reduce procrastination. You'll also remember the content better. These include flashcards, mind maps, practice questions, past papers and explaining to others like your friends or family. I would recommend you use flashcards to memorise content and practice questions and past papers under timed conditions (even if you get questions wrong that's okay, you'll learn more from your mistakes). Don't just read from a textbook. A textbook is great to read when you're trying to understand something (like the other person said CGP books are simple and good for this) or learn something brand new, but is a terrible way to revise or memorise content.
Also, whilst revising make sure to take breaks (have a look at the pomodoro technique) as this will increase your productivity and make your revising more efficient.
If you have any questions feel free to message me on the student room or dm me on instagram @studymed_eda (I have content on here about revising, study tips and motivation)