One way to get a better grasp on any subject is to get as many books about the subject and photoread them. Just a light preview 2 3 minutes at the most. Photoread and perhaps a 10 to 15 minute postview. If any book draws your attention give it a bit of activation time. Then focus on your class textbooks. Treat each chapter as a book in itself. Take as much time as you feel you need to activate the book give yourself the understanding that since you're having trouble with the subject activation may take a tad longer. (still a Lot less than with regular reading )

Alex