Okay. First of all, I think it's your call to decide what's best for you. You mind find this silly, because then why would you be asking all of us? What i'm trying to imply is that if you haven't had the chance go to over the material you want to go over, why take the exam when you're not ready for it? First of all, that's tanking material that was supposedly well-spent on studying (why would you ever wnat to restudy past material...?) and second, do you want to put the effort and time into doing it again?
Personally, if you're this worried about the MCAT, I think for your own sanity as well as for your success in the future with applications, postpone it till you are ready. Plan out your time. Figure out how long that will REASONABLY take. We all study differently, and for you to ask whether or not to postpone it...well, that simply depends on the person, does it not?
Look. You're trying to become a physician. Apply the same principles a physician would for his/her patient. Plan stuff out. Make reasonable goals. A lot of people just sign up for a test without realizing-will I have enough time to do this. And then they wait until three weeks before the exam or something, and realize OMG i don't. That to me is sheer ignorance.
Wasn't intending to be mean-just want to make a point across. If you're not satisfied, don't take it. Does this mean you might need to postpone applying this year? Possibly. But I can assure you, every adcom out there will echo my opinion in that if you're not ready, don't apply. And if your mcat is substandard because you took it without being fully prepared, you were silly to take it then. And, honestly...with that mentality, I personally wouldn't want a physician who only half-@$$'s their work.
All in all, I'm just trying to tell you to shape up. Not because you're an idiot, but prepping for the MCAT requires some discipline and commitment. Make a plan, stick with it, and execute. From now til your test day, you gotta be on fire (Again, don't burn-out, but stick to a plan.)
Only reason why I say this was because I was in an nonideal situation and I really needed to change who I was to be ready. Did I take an additional year off because I wasn't ready? Absolutely. Am I happier now that I did, and got the MCAT score I wanted? Absolutely.
See my link below if you want my story in the matter. Cheers, and good luck.