Hi there. It could be
Dawn Phenomenon or even something called
Symogi (?) effect. Some people say it helps to have a snack before bed in order to head it off. Sometimes an adjustment to when you take your meds (at night, for example) helps. But! I'm surprised neither your doctor nor nutritionist could tell you anything about
this. So, yes, maybe it
is time to see an endo. In the meantime, google those two things and see if you can find better suggestions, or at least better explanations than I can give. Sorry for this problem. Always, something.....