Well, I guess if you study just one subject each day, that'll help. There's probably already a hell of a lot of stuff to study for each subject, so cramming will most likely not help you out.
I'm probably not going to end up taking Physics because I don't need it, but I heard it's the hardest out of all the sciences lol.
Just keep positive! :] Tests in general are so dumb because they honestly just test you specifically on how well you remembered the information, but the funny part is that after you take any test, after a few weeks, you'll most likely completely forget everything you "learned".