The answer to your question is "YES" you will need to take medication along with exercise well as healthy diet.
Normally for the BORDER LINE DIABETIC- ( HbA1C-7.0-7.1) or 120-130 mg/dl, exercise and the diet modification will be a great help and may no need any kind of medicine,
But in your case your have HbA1C -7.4 OR 165 mg/dl , is to much to to taken care by exercise / diet control alone, as far as exercise and diet control alone is concerned it will help to work of difference of 10-15 mg/dl. so to cover another 40 mg/dl in your case help of medication is needed.
More over the diet and exercise are variable factor , as some day your eat alot of sugar but to a birthday celebration, other day due to climate problems may not be able to reach the GYM , and the long term commitment for the hardcore exercise and diet is very rare to see according to long term research, more over extreme exercise will give greater toll on the bodies joints as well, leading to joint problems in future.
So best treatment is combination of all 1) exercise, 2) diet control 3) medication. This regimen will take you to long way.
DIET FOR DIABETICS
1) Fiber-rich foods- Fiber can decrease the risk of heart disease
and help control blood sugar levels. (such as vegetables, whole grains, legumes (beans, peas and lentils) and low-fat dairy products.
2) Good' fats - such as avocados, almonds, pecans, walnuts, olives, and canola, olive and peanut oils.
3) Foods to avoid - Deep fried , high oil, high cholesterol
and high complex carbohydrate
Best way is to monitor daily intake of food and calorie , recommend calorie is about 2000 kilo calorie, so needs to check how much you eat rather the what to eat.