This confusion is common, for the medications that most people are put on to treat diabetes can cause hypoglycemia if overdosed or if the patient delays a meal or perhaps does not eat the usual amount of carbohydrates in a normal meal. So diabetics can and do suffer from hypoglycemia. Your father's glucose levels of 200-220 indicate that he is indeed diabetic, but the hypoglycemic symptoms happen when his medications cause his blood sugar levels to drop too much in response to medications or perhaps to stress such as fasting before surgery. Hypoglycemic reactions not only make him feel tired and confused, but can be life-threatening if he happens to be driving a vehicle when they happen. He needs to take careful note of when they happen the most often, treat them immediately with some fast-absorbing carbohydrate such as orange juice, and discuss this with his physician. If it is happening often, he may need to have any medications he is taking readjusted. If he is taking insulin or any other medication to treat his diabetes, it is imperative that all meals are regulated carefully -- each meal should occur at the same time of day and each breakfast, lunch, and dinner meal should contain the same amount of carbohydrates. If he does not know how to regulate his meals this way, he should be referred to a dietician who can teach him to do so.
I'd also like to suggest that you/he find a doctor who specializes in diabetes because many doctors with other specialties just do not have the expertise that's needed.
All diabetics, and especially those with confusing symptoms, need to work with a diabetes doctor. I am not a physician, but most adults who are diagnosed with diabetes have what's called "Type 2" ... it is by far the more common type of diabetes and can be manage well.
Look for someone who is called an endocrinologist or a diabetologist. Usually, a general-practictioner doctor can refer you to one of these specialists.
It will be very important for your dad's long term health that his diabetes be treated properly. It does take time.