I'm in a classical mechanics class now. On our exams, most questions are quantitative. And in general, besides the theory part, all physics problems just require you to gather formulas, manipulate them a little bit by using other formulas, and come up with an appropriate value. In the question, you are given all the information you need. For our exams, they even give us a formula sheet, with every formula and equation we can possibly need. But even after all this, physics remains to be one of the most challenging subject for many students, including myself. I just don't get it. It seems like it should be so easy. Grab a formula or two, and manipulate it until all the given quantities can fit into these formulas. But yet, even after all this, its not easy to do, but it *should* be. Sorry if I'm not making any sense. I'm a student, and most of you already know this stuff, so try thinking as a newbie to physics. 

Edit: Although this seems like a general study question, its actually a very specific question. I'm a really good student, but I think I've met my match with physics. It seems you just cant 'memorize' things in this class, like you can with any other class. You really just have to understand it. And lately, I've just been so discouraged to study since no matter how hard I study, I do really bad on the tricky exams. My study routine goes a little something like this:

1. Watch pre-lecture video that explains the current chapter, and take notes on that.
2. Do the weekly homework, which itself is pretty challenging.
3. To study for the exams, I do a BUNCH of practice problems from previous semester exams that they supply us with. I literally go over and do 5 old exams, one question at a time, and I understand everything perfectly-at least I think I do, until the REAL exam comes around, and I do absolutely terrible.

I don't know what else to do at this point.