Could it be the drug you are taking for your for your diabetes causing the skin discoloration? I know that the fatigue, thirst and blurred vision is you epilepsy meds. It all depends on which one.

It could be diabetes. I was told by a rheumatologist that certain areas which looks like it might be dirty can be an indication that diabetes will happen in the future even brown like creases on neck. Excessive thirst and fatigue are a big sign. I don't have diabetes but a lot of my family do. It might be wise just to get a simple pin prick and see your Dr because your kidneys and of cause your life are at risk. . It is often a disorder that many people don't know they are walking around with until very severe

I don’t know about Diabetes, but I know a few of them are symptoms with epilepsy. Whether it be a medication side effect or seizures.

I know that personally, I experience fatigue, blurred vision, and excessive thirst but these are all symptoms of my medication. Maybe your medication is causing some of these symptoms as well?