Scores Not Improving

So I've been practicing consistently with NS, EK, AAMC, Kaplan, and TBR but I don't seem to be improving significantly. At best, I reach 508 50% of the time. I understand the basic concepts because I can always answer end-of-the-chapter questions or those without passages reasonably well, but sometimes the passages just seem so incomprehensible to me, especially for the chem/phys section. I try to read the carefully but it feels like the passages tell you "1+1=2" and the questions ask "based...

Scores Not Improving