I struggled with this section a LOT too... but finally I got the score i needed this time... All I can say is that keep practicing under tightly timed conditions. For this you need practice tests (I used Dr. Collin's, Kaplan, and some random MCAT readings I found on Web). Do each practice test and try to finish each of them well under 50 mins while retaining most of the information you read about.
And after all that, do all three pearson tests!!!
Good luck