I think this is one of those 'people who have lupus are at a higher risk of developing diabetes or heart disease' and so on. My husband was just diagnosed with it in January. It was quite a heartbreaking shock. His blood sugar was at 348. He has his diet (albeit not his exercise) under control now and his blood sugar stays under 140 without medication, usually it is between 120-130 at night. Type 2 diabetes... the pancreas makes the insulin hormone to handle the blood sugar. I think it's when your body stops recognizing this hormone and the ability to 'deal' with sugar becomes impaired.
I think there could be a hormone/autoimmune link. My mother has graves disease and is pre-diabetic, and my great grandmother had diabetes and probably also had lupus. The two seem to run hand in hand in my family.
My husband cut out ALL cokes, coffee, and all sweet stuff. I'm still trying to convince him to stop all bread, pasta, potatoes. Whole grain is better, no bread at all is even better. Oatmeal is good at absorbing and removing bad fats. Cinnamon, garlic, sweet potatoes, flax seed, and fish high with omega 3's are all examples of beneficial foods. Watch out for cold medicines btw, 1 dose can spike your blood sugar through the roof. Chloraseptic makes some sugar free cold meds.
I'm sorry you have this now on top of everything else. It's not all that bad once you get it under control. Another thing, try not to take your blood sugar meds too late at night either, it can make your blood sugar do a rollercoaster while you sleep. My husband woke up with very high blood sugar in the mornings until we figured this out. HTH.
Diagnosed with SLE lupus October 2014.