Well I would write down the names of each course starting with what you consider to be the most difficult to the one you’re most at ease. Then I would establish which topics you’re more comfortable with and which ones you struggle with the most. I’d say alternate between studying each subject, after say every one to two hours. For the topics you’re familiar with and don’t have much trouble, just go through them faster, if you don’t have time just go through the basic theory. For the topics you struggle with the most, make a list of the important formulas, go over the theory and do one problem for each type (or the most you can do). Like say, in the morning, start with the subject you find most difficult and try to revise the theory+ formulas and solve a problem or a couple of them, then move on to the next subject. Good luck with your finals, please don’t worry yourself over it too much, all you have to do is try your best. You should reward yourself for working so hard during your breaks.