It is perfectly normal to be a little confused in CR at the beginning. I personally studied from the Powerscore Critical reasoning guide which helped me improve my CR score tremendously. If however you have tried that guide and it did not work, I believe you may benefit from taking an additional course in verbal. If you are willing, there are some great GMAT prep companies that can help you with your preparation. I would highly encourage you to consider
e-gmat verbal online or the
e-gmat verbal live course. They are both amazing courses especially designed for non-natives. They offer almost 25% of their courses for free so you can try out their free trial to decide which one you want to go for. Plus the
e-gmat Scholaranium which is included in both the courses is one of the best verbal practice tools in the market.
Hope this helps. All the best.