Your situation is almost exactly like mine. Don't get discouraged! I used the same materials as you, and scored a 580 my first attempt(was scoring 670-690 on practice tests).
The second time around I just did a ton of practice exams, and questions. The key was an
error log. I just wrote down the types of questions I got wrong, and then reviewed the material. The confidence from taking so many practice exams really helped me too. I did not have the best study plan, but this method worked for me.
I don't know how you felt test day, but keeping the faith helps. I scored a 720 my second attempt around. Grind it out no matter how poorly you feel you are doing during the test.
Materials:
GMATclub tests. They helped a ton. Sounds like you are going to have difficulty finding new sources of questions. The bonus pack of questions from GMAT prep is also great, and is reasonably priced.
Grind out the Manhattan Tests. I found their quant to be much more difficult.
Manhattan SC – This is the only book I truly believe to be essential no matter the study plan. The one caveat is that I'm not familiar with your SC book.
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