Please help me.

Prior to the test (may 26), I had spent 1 1/2 months studying, but I cannot believe that I did so poorly - 530 (41 Q, 23 V)

Here are the study guides that I've used:
+ Barron's
+ Kaplan Verbal
+ Kaplan Prep
+ Kaplan English Grammar

Since English isn't my first language, I expect to have a lower verbal score than the quantitative score, but did not expect it to be this low. :( (I was frustrated that I did not finish the quantitative that I barely could concentrate on the Verbal section).

As a side note, I took the GRE before graduating from college last May 2006, and I've received 780 Quantitative, 630 Verbal and 5.0 on Writing, resulted a total of 1410.

The last two weeks before the test, I've completed 6 practice tests, resulting between 630 and 720.

What bothered me the most is the inability to finish the quantitative section, which I believe to be my strongest area since I've graduated with a chemical engineering degree and currently working as an engineer for a petrochemicals company. Through out my practice tests, I've focused on Permutation and Combination problems since these are the trickest problem sets that I'll have to face. But still, it's shocking to me that I did poorly on the quantitative section because I've got hung up on several questions, which most of time were spent on them that it did not leave me enough time to finish the test. This never happens to me during the practice tests.

What annoyed me the most is the test center. Having to raise my hand every time I need new non-erasable papers while the lady takes her time to deliver, had distracted me and threw my concentration off.

Currently feeling unease about my result, I cannot take my mind off this poor performance. I'm planning to retake the test in mid September; this will give me 3 months to refocus and restragetize my preparation.

I intend to start doing practice tests in similar setting as the test center, with the corporation of non-erasable papers and markers. I only hope that this tactic will provide me the confidence that I'll need to achieve a better score.

Question 1: I don't know if I should take one of those GMAT prep course or hire a tutor for the summer?

Question 2: I did not take the advantages of the Free 2 practice tests from the MBA.com website when one had registered the test. Although I took some simulation CD tests with a timer prior to the test, I felt that I was under a lot of pressure at the real test that had impede my ability to concentrate. Where can I obtain more CD practice tests that simulate the real CAT tes?

Question 3: Even if I score higher on my next retake, will this score jeoparadize and/or pose a significant drawback on my applications for business schools? I want to pursue an MBA that focuses on Non-Profit (and/or international relation).

Here are my educational and leadership backgrounds:
+ 3.4 GPA Chemical Engineering from a prestige university
+ President of Key Club (400 members) - led many community services in the area, was recognized for leadership skills and services
+ Dean's List for 2 years (4 semesters)
+ A member of an honor fraternity (4 yrs) - several leadership/mentoring opportunities
+ An op. engineer for a petrochemical company
+ Founder and Chartered a communication/leadership oppportunity club at the company that I work at.
+ A volunteer (work during nights and weekends) with a non-profit organization whose goals are to improve the lives of third world countries through digital transfer. - Currently a project leader that will expand into another business function. (I work in Texas, the organization HQ locates in NYC and has offices in several third world countries). If opportunity is given, I would like to take several months prior to starting business school to work full-time for this organization.
+ A member of a small communication club in the area - helped revised and brought life to the club (was recognized).
+ Completed a half marathon (Spring 2006)