This is sort of redundant, since Gary covered the territory pretty thoroughly. I just want to repeat a few things he said, simply to pile on and add emphasis.
If you are very insulin resistant -- which is what it sounds like -- then as Gary said, all three of these will make a difference:
1. Losing weight
2. Exercise
3. Low carb diet
And they are closely interrelated. Doing #3, for instance, will have a huge effect on #1. When I switched to a low carb diet, I dropped almost 20 pounds without doing ANYTHING else. Didn't change my exercise pattern, meds, or anything. The weight just fell off when I stopped consuming carbs.
One other thing that's very worthwhile, if you haven't done it already, is to read this book:
Richard K. Bernstein, Dr. Bernstein's Diabetes Solution, 4th ed. (New York: Little, Brown and Company, 2011)
Bernstein is a true pioneer in the management of diabetes. Just as an example, he invented the basal/bolus approach that is now pretty much standard practice. But importantly, he is himself a Type 1 diabetic so he has more skin in the game than most doctors and writers. His book is the bible for me and many others. Regardless of how much of his advice you do or don't choose to follow, his book will give you a more thorough, grounded understanding of practical day-to-day management than even many doctors possess.