You know, if I had to do it over again, I would have learned things differently. Just knowing what I know about the MCAT, and how it tests... I know I would do things differently if I were to go back to general chem and general bio. I did well in those classes, but struggled with the MCAT.
I don't know how to change it for you... I think some schools teach in ways that are conducive to carrying info over to the MCAT (and DAT for that matter, according to friends), and some definitely do not.
One of the best things I did, was figure out who the lab instructors were in my Bio classes, then switch into the labs that had TA's that were applying to medical school (I managed to do it twice). So, when there was extra time, or everyone was done early, I could pepper them with questions and get advice.
Hang in there, keep your eyes open to opportunities and don't pass up the chance to explore different things (including career opportunities) that interest you. My good friend was pre-med until last spring, when she shadowed an orthodontist... and she just fell in love with it. Now she's applying to dental school. She's shocked, everyone's shocked... but it's definitely the right road for her.
Hang in there, and best of luck!