Frustration: MGMAT guides and OG problems - Please help!

Hi guys ,

this is my first post here in this awesome community. Over the past 3 weeks I read a lot in this forum or reviewed OG problems and it was amazingly helpful. Thank you all!

Currently my frustration increases because I have only 4 more weeks until test date and I feel like I'm failing on too many questions in the "moderate" area. I hope you can help me out, but first some information about me and my studies:

About me:
I recently finished my undergraduate degree in Business Administration in Germany. Now I'm planning to do a top graduate programme in Germany (deadline for application is February 2018), so I need the GMAT.

Materials I use:
- MGMAT Strategy Guides 6th edition (complete pack with 10 books)
- Official Guide 2017
- GMAT ToolKit App (e.g. when traveling or waiting)

Current progress:
I finished the third guide "Word Problems" today. So I covered the major topics of FDP / Algebra / Word Problems until now. I go through the theory of each strategy guide writing flash cards and learning and repeating the theoretical concepts (as well as the strategies like Smart Numbers, Work Backwards, Testing Cases, Draw it out...).

OG problems:
I do OG problems only through the "mid-term-quiz" and "final-quiz" in each of the strategy guides. I do the "easier set" and "moderate set" and leave the "harder set" because I am "only" aiming for 600+. This way I solve around 45-60 OG problems per strategy guide. As a result I solved a total of ~160 OG problems until now, shared over the topics of FDP, Algebra and Word Problems. (Question number one: Is that enough?!).

I review the wrong questions but I find the solutions and explanations in the OG very complicated and not useful. So most of the time I review the questions using this forum to see different approaches to solve a problem.

My biggest problem:
I find myself reviewing all the theoretical concepts and understanding them well in my opinion. I was always good in verbal but never a pro in math and I had a hard time remembering and relearning all the basic math concepts. I solve the majority of the problems after each chapter in a strategy guide correct with no major problems. However, when I move on to the OG problems, I get approximately 60-70% right on the "easier sets", and only 30-40% right on the "moderate sets".
I feel depressed every time when I spent 2-3 days working through a strategy guide, solving the majority of the practice questions in the strategy guide right, and then get such a bad quote in the OG problems.

I tried to figure out why I miss the OG problems (especially the "moderate" ones) that often, and for now I realized that I have to read most of the questions at least twice to know what it's asking (because of the weird sentence structure and questions). I also have a very hard time doing the "textbook" math and setting up formulas based on the problem. That is why I don't like the OG solutions and explanations that much, because it's almost every time an algebraic solution.

So far, I really don't know what do to. I mastered every challenge in my life but this exam is driving me crazy and I'm always scared that it's possible that I can not reach the 600+ because I am not smart enough for this kind of math/logic. However, I do have hope that the verbal part fits my skills and talents a little bit more, but I plan to begin with verbal in 14 days at earliest.

I would be really thankful if you guys could help me out with some suggestions or ideas what improve or what to do next.