mcat100,
Was that your diagnostic score? If that's the case, expect to improve significantly with proper/structured/efficient studying. If that is your previous actual MCAT score, I would suggest revisiting the basics and getting a foundation in the various subjects before sitting down to prepare to take the MCAT.... (if that makes sense?)
The first time you see phys, chem, orgo, bio should not be when you are starting to study for the MCAT. Khan Academy is a good resource for anyone who isn't familiar with phys, orgo, bio, and chem.
It could also just be that you're a poor test taker. No offense... but that was the case for me. I sucked at taking standardized tests. I just never knew how to properly take an exam even if I knew the content. If that's the case for you as well, get the princeton review reading comprehension for the LSAT and the Princeton review Logic games bible. These two books teach you how to read and answer questions efficiently. You might be thinking that they are unrelated to the mcat. BUT IF ONLY people knew how to manage their time and read critically... a lot of the worlds problems would be resolved. You get into a certain mindset where you are looking for loopholes... searching for things you can eliminate so you can get to a 50/50 scenario. Its pretty exciting. Those books really helped me become an efficient test taker. You can THEN apply those skills to the MCAT. So if you were presented with a question, you'd know what choices to eliminate... which choices to keep.... and how to read the passages critically to support your answer choice.
Hope that helps.