Please, suggestions

Hy guys, I'm writing this post because I really need some advice from you. I've been preparing for the gmat for almost 4 months, every day studying an avarage of 3-4 hours. After attending a Veritas Preparetion Course of 7 weeks I did my first two gmat practice tests and I got two 580, but in the first I scored very high in math (45) and poorly in the verbal and in the second the situation was the opposite (37 verbal, 25 math if I remember well). Not happy of my results, I decided to continue studying in order to improve my scores and thanks to this forum I could understand what books to buy and what practice tests to take. So, I used the following:

- Official guide 12th edition, plus verbal e quant books:
- Manhattan Sentence correction (wonderful);
- Critical reasoning bible.

The thing is that: I used the five 800.score CATS, 2 Manhattan CATS and I'm currently using the Gmat club tests. I really don't know what could be my potential score at the test day, because I had totally different results from these test:

- 800.scores tests (I found the quant part extremely challenge, requiring a lot, a lot of calculation and intuition. I scored poorly):

Verbal Quant
800score 39 38 640
800score 40 38 650
800score 34 0
800score 37 0

- Manhattan Cat (I've also found them very challenging, in particular I realized that after doing well a couple of problems the algorithm already gives you 700-800 questions, and they are very trick and difficult. I had to do this test untimed because I was not able to answer the 700 questions in 2 minutes. I needed nearly 4 min for quest. I hope the real gmat is easier, otherwise I could just dream on a 650-700).

Verbal Quant
Manhattan 1 - 46
Manhattan 2 31 48

Gmat Club tests - I found them more easy than the 700 manhattan cat questions (for me as difficult as those of the 800.score cats), but even though I have an avarage of 27-30 question right over 37, my percentile is 50-60%. At this point I don't understand if these tests are condidered difficult for the % they give you or for the question by themselves. In the Manhattan Cat you can get a 46-47 even if you have answered incorrectly 15-17 questions.

This said, I'm not able to predict what could be my final gmat score and what is the best aproximation of the real thing (apart of the Gmat preparetion CATS). I hope 800.scores and Manhattan CATS are far away from the real Gmat. Furthermore, are the gmat club test questions similar to the 650-700 question of the real Gmat??? I hope so, because in this way I could have good chance to do correctly 25-32 questions at a 650-700 level. Please helppppppp