Have you tried:
1. Powerscore CR
bible: Usually works very well for most people. My personal comment is that after reviewing this book, the right answer choice just shines through. At first, when doing practice questions, try to focus more on the structure of the passage ie try to identify the conclusion, premise, counter premise etc and then try to apply the CR bible techniques. Here is a good CR resource, if you haven't got this one already. Its basically a summary of the CR bible book cr-guide-100473.html
2. MGMAT SC
book: its all you need for SC. Get in the habit of taking notes and after each chapter, don't forget to do the suggested questions from OG. Make sure you review each OG question. Even the ones you get right.
My GMAT debrief: from-620-to-710-my-gmat-journey-114437.html