Here is my two cents which may be totally off the wall and may not be correct but I will state it anyway. When you exercise, your muscles need energy. You do not seem to be taking in enough calories to provide the energy necessary for the exercise and your body is trying to compensate. Maybe you should increase your caloric intake while keeping your total carbs down. Your body may think it is in starvation mode.

Seeing your doctor is your best move and if necessary, going on insulin may prove helpful. Taking insulin is less painful than "testing". Any particular reasons you are resistant to starting insulin? Fear? Financial? Inconvenience? You do not need to respond and I am not trying to invade your privacy. I was just wondering if you have thought about your reasons for not wanting to cross over from oral meds to injectable. Just something to think about before you see your doctor.