The point that I'm not sure if you're getting is that salt doesn't have as much to do with diabetes as does everything else. Salt contains sodium, which affects your blood pressure, which often affects diabetics (most of my mom's side of the family are either diabetics or pre-diabetics, and most of them have blood pressure issues), but it doesn't affect your blood sugar.
Sugars, carbs, fats, and proteins are turned into useful substances with insulin. Insulin is a natural substance that the body produces in the pancreas. When the pancreas either doesn't produce insulin at all (type 1), or the insulin it produces is not of sufficient quality to effectively break down foods (type 2) then insulin either has to be administered from an outside source, or sugar consumption has to be limited to what the pancreas' insulin production can process.
I have a coworker who had diabetes his whole life until about 6 months ago when he had a pancreas transplant. He said he was always able to eat everything a normal person could including beer and fatty, sugary foods, he just had to balance his insulin with his food consumption. One thing that was always obvious with him whenever his blood sugar got low was that he would become a cranky little bitchbag that nobody could stand to be around.
^ This.
One of my sisters was diagnosed with Type 2 about three years ago. She went on a very strict diet and did a ton of exercise. Within a year, her doctor told her she was no longer diabetic, and said she should really be a poster child for how to do this right.
Definitely find out if you can control it with diet, that way you don't have to screw with medications. Good luck to you!
This sister of which you speak... Does she look like you? Is she single?