As far as my troubles, logical reasoning, especially assumption. And logic games, but I know I need major practice on those.
Have you gotten your hands on the powerscore bibles (the one for logic games and the one for logical reasoning)? The one on logic games is especially good. I picked up 10 points on the LG section alone after reading it. And the LR version breaks LR problems down by question type and gives a great explanation of assumption problems.
If I were in your shoes, I would postpone the October test, order both of those books, and spend the next 3 months mastering the material.
Whatever you choose, good luck!