Heart disease

I know this kinda seems stupid to ask. But I was diagnosed with type 2 diabetes 5years ago . I was put on oral medication and changed my diet completely for the better, my question is would it be possible that I may have had heart disease before I was diagnosed with diabetes? And would that may have what cased me to become diabetic ? The reason I ask these questions is while n medication and eating right my blood sugars were still spiking. Can some one help me find the answer?