Can diabetic neuropathy affect the scalp and face too ? or is it secluded to just extremities ?

You would have to be a type one diabetic to experience neuropathy significant enough in my opinion. There is some long-haul Covid symptoms that include tingling of the scalp. I’ve also seen it in some inflammatory conditions. If you do not already have some pretty significant drop of the hands and the feet, Then I doubt you have it on your head and face.

Yes, diabetes can affect cranial nerves, and indeed one needs to carefully control blood sugars. A neurologist could work well with an endocrinologist.