Hello and welcome to ‘Ask A Doctor’ service.
I have reviewed your query and here is my advice.
First thing I want to say is "Well done" .
Your A1C result is perfect, and this mean that your
diabetes is under control.
Fatigue and inability to concentrate can be a symptoms of
hypothyroidism.
At the other side, losing weight is another important symptom that should be taken in consideration and can be also a sign that your thyroid is not functioning properly.
Anyway if you were my patient, I will suggest to do the thyroid tests:
TSH, fT3 and fT4 and a
complete blood count test to see if there is a correlation between your actual symptoms and your thyroid situation or if you have a possible
anemia that can explain the fatigue and inability to concentrate.
Hope I have answered your query.
Let me know if I can assist you further.