Study smarter, not harder....
I got a C+ on my first calc 2 test because I studied inefficiently. I literally studied the DAY OF my second test for a few hours (but studied very efficiently i.e I tried to figure out what might be asked and assessed my knowledge from all angles) and ended up setting the curve.
I agree. There seems to be nothing wrong with the amount of EFFORT you're putting forth, but something fundamentally wrong with how you're doing it. You can spend hundreds of hours doing the same thing incorrectly and still not see the results you're achieving.
Biology is mainly about memorization (sorry, but true). There's not very much critical thinking involved, which is the entire premises of physics and chemistry. Physics is more than "memorizing formulas." Physics is the application of mathematics to real-world situations, so you have to step out of the box in terms of how you've traditionally studied. You cannot memorize every possible scenario that will arise when it comes to a physics problem. It's not a good use of your time. A good use of your time would be to understand the approach of each problem, and how to come to the conclusions another student would. Start asking yourself "why is that the right answer?" rather than "what is the right answer?" Questions like: "what information in this problem can I use to derive the answer the question is looking for" will start your problems much easier than "what problems have I seen that are just like this?" and you will find yourself focusing on a completely different aspect of the problem.
Quite frankly, I was in the same boat you're in-- I just didn't "get physics" when I first took AP physics in high school. I didn't have any clue how to start a problem, or what I was doing. It wasn't until much later in my life that I started to pick up on physics because it was explained to me differently. I didn't understand circuits (AT ALL) until I took neurophysiology, which uses circuits as a model for how neurons communicate to one another.
I used this realization that I seemed to base all of my education primarily on my memory to buffer my studying for the MCAT. I started to rely more on logic and cognitive thinking rather than pure memorization and practice problems. Maybe a good start for you, if you're really struggling, is to purchase an MCAT Kaplan book. Sometimes just having something explained to you in a different context will provide new insights.
I also find that if I try to tutor someone in a subject, then I master the subject much more because as I am explaining the concepts to someone, I am solidifying them to myself.
Remember that the MCAT is your next hurdle in your journey to get into medical school. The MCAT is not a memorization test. It is a critical thinking test, so you should start to train your brain to think logically about problems because your memorization skills will not help you as much on the physical science section of the mcat. I did not find my memorization of biology to be very useful even in the biology sections, and I reasoned my way through organic chemistry.
Reasoning trumps memorization... in your premed courses anyway.
My biology professor's favorite quote was: "Doing the same thing over and over again in the same way, and expecting different results is the definition of insanity."
So do yourself a favor and start thinking rather than going through the motions. You're not a zombie, so don't act like one.