The crux is that you cannot master it all. You need to sort the wheat from the chaff. You will be overwhelmed if you try learning everything. If push comes to shove, favor clinically relevant material over minutiae. It is more important for clinical years and long run. Good teachers (most MDs anyway) will tend to prefer it in their test questions.
Pop some Gingko Biloba. Consider referring to First Aid and BRS review materials to help narrow your focus. Use a highlighter but don't make the mistake of highlighting too much--I see a lot of silly peers doing this. It defeats the purpose. gtg