Verbal | Finding OG CR too difficult

Please help! I am going to take GMAT in September and want to apply to ISB round 2.
Though I am improving in SC and RC but my CR is pathetic. And coz of my poor CR result I am feeling very discouraged. I don’t know why I am finding OG CR way too complicated.

Is the reason could be this that I haven’t studied any book like power score CR or Manhattan CR? Though I have rough idea about what is a Premise , counter premise , assumption, conclusion , keywords etc.

Do only I am finding OG CR
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