Taking standardized tests with diabetes

I am taking the gmat this week. Kind of nervous, yes - but focusing on the positive. I'm not the best standardized test taker in the world, but I feel like I've prepared so hopefully my studying will pay off. Sometimes I feel so unlucky to have developed a disease that is relatively rare statistically speaking. A multitude of stars must have aligned for this to happen.
Other times, I feel rather lucky that I was free of the diabetes burden for almost 23 years.
I didn't have to deal with being diabetic in school or taking tests with diabetes. I wonder how and if it would have affected me as a student. It's one more thing to deal with on top of SATs, college applications, etc. I imagine like everything else, having normal blood sugars is best but I wonder if and how high blood sugars affect mental acuity or problem solving ability. Like most people, I think I have the tendency to feel lethargic but I feel like I could still focus if I had to...I think. Who knows... Anyway, this will be my first standardized exam with diabetes. In order to bring my meter and insulin pen into the testing area, I had to submit a petition along with doctor's note to the test administrator. It felt strange writing to disability services to request something so basic, but those are the rules. More or less the letter expressed something like "If you don't let me bring my meter and an emergency source of glucose, I could potentially pass out right here on to this keyboard." I'm not sure how I feel about having "special treatment." Sometimes I feel guilty about feeling like I'm taking advantage of things. For example, if I'm at a restaurant and my food is taking a while or I want something to eat RIGHT NOW, I'll say I'm diabetic. And maybe I might be on the low-ish side... Other times I feel entitled to whatever benefit I can muster because practically nothing could make up for it.