Taking the Exam for a Disabled person - ADHD and Dyslexia

Hi all, kindly need your help in planning my next move with the exam

I took my exam a week ago and have been studying for roughly a year without major breaks. My score is 660 Q31 (37%) V49 (98%) and canceled it. My target score is 700.

Regarding the verbal, I have no complaints and I don't think it was a fluke, since I answered all of the questions with confidence.

The quant section, however, is a completely different story:
I have numerical dyslexia and severe ADHD, which means I have some trouble in numerical operations, eg no matter how hard I try, I cannot memorize even simple 1-digit multiplication. Randomly ask me what \(7*8\) is and I will pull out a pen-and-paper and start counting. This is obviously bad for the Quant section, even though I have no trouble with the actual material; I've done the Official Guide and the OGreviews with no trouble, considering I often use calculators/extra time anyway.

In any case, I know that GMAC offers some leniency for disabled test-takers. However, from what I can gather, the process is long and tenuous, with no guarantee that they'll consider my case. For the record, I also lack a major paper trail (doctor's diagnosis) since I have just been diagnosed a few years back, and my first doctor actually didn't give me a written diagnosis, only verbal.

A bit of background, I hold a bachelor's in pure maths from my country's best engineering school and I currently work as a software engineer at a local hedge fund. These facts actually suggest that I have no trouble in quant reasoning per se but I do need my calculators and/or some extra time.

Is there any tips for my case on the GMAT? Is there someone that has successfully made a case with GMAC about their disability?
I'm also retaking the test in two weeks so wish me luck!