I think your issue here is going for practice without a proper conceptual review. The OG is awesome for practice, but its tips and strategy sections are subpar. I suggest you invest in some books that cover your weak areas. Here are a few suggestions:
- Manhattan GMAT RC, CR and SC books
- PowerScore Verbal Bible or CR Bible + SC Bible
- Kaplan Verbal Workbook

Depending on your weaknesses, you should go for the materials that fit your needs.

When you said you reviewed your answers the day following your test, did you also review the relevant concepts? for e.g. if you were getting majority of Pronoun questions wrong in the SC section, did you go back to some reference book and checked the section on Pronouns? If not, that is your problem. The same principle applies to your RC or CR sections as well. Analyzing your answers is great, but you should also get back to the concepts where you are getting majority of the mistakes. For e.g., in CR, you should divide your mistakes broadly into Strengthen/Weaken/Inference/Bold Face Role etc and then go back to the basics to refresh the concepts.

The references mentioned by Dana J are great books and I have used some of them, so please read them after you analyze your answers and you should be doing better.