The op has explained his dilemna clearly.
For many the exams are an obstacle to somehow overcome. Do not be ashamed of studying for the exams because thats how things are. Those who have advanced in higher education know this well. Most will have attended many presentations on exam techique throughout their career. One of my old students - now a Training Captain with a major british airline - always considered a pass mark above the minimum wasted effort. However the pass mark is not a barrier to learning. Exams are only a small sample of knowledge and there is so much more that the instructor should include in the practical flight training.
If your instructor is disinterested in your ground school then find another, they are not right for you. Most instructors, in my experience, who claim they do not charge for groundschool do little of it. Be prepared to pay and expect the best, not just for the exams, of course.