Why am I doing so much worse on practice exams?

<p>Hello!</p>

<p>I'm a high school junior who is taking SAT tomorrow.. (yay)
This is my second time taking it, and last time I got 2230.
(790 M, 770 W, 650 CR)
I am aiming for 2300+, but I have several problems that I want to discuss...</p>

<p>The first question is that is AP exam a lot different from SAT CR?
Cause I normally get 5 on AP practice exams, but I do relatively mediocre
on CR sections... The fact that I'm an international student might explain
low CR reading score, but my performances on AP practice exams suggest otherwise..</p>

<p>Second, so, in order to improve my SAT reading score (for the past month) I did three sections of CR everyday and memorized 1000 vocabs. But my scores on those or practice exams are REALLY LOW. It's around 550... </p>

<p>I really don't know what's going on....
Please help me! I'm really worried about tomorrow's exam..</p>