Th scoring with the GMAT is tricky...your high accuracy percentage does not always mean a high score. For example, I took a practice CAT today, and I missed 12 problems in Quant and 16 in Verbal. 12 out of 27 is only about 66% accuracy but I received a Q48 score. Compare that to my Verbal. At 60% accuracy I received a verbal raw score of 30.

I would suggest you go to mba.com and download the test prep software and take a CAT so you can see your baseline and weaknesses. After taking that, post a reply... make sure before you close out the test (on the screen where you get your score) write down your "raw scores" it will something like Total 600 Quant 40 Verbal 30...once you pass that screen you cannot go back to it...

I took the first GMATprep test today, and here's the result:
650
Q49- 8 wrong answers and 25 minutes extra time!
V30 - 12 wrong answers and 13 minutes extra time!

I took the test at home , and during the test I had a few discussions with my friends! when reviewing my wrong answers in quant, I could easily find the right answer in less than a minute! so, I think for now I need to focus on verbal, but I don't know how to improve it?

I would say retake it without unteruprions in a few days. Until then look at what you missed. Since you're Iranian like me quant for some reason comes natural to us (probably because it is showed down our throats for the first 18 years of our lives) my struggle is verbal as well. I am starting to get the hang of it finally but if you're aiming for a 750 you will need more than three weeks to prep. Break down your errors into three categories reading comp, critical reasoning, and sentence corrections and work from there...