If you take in more than you burn off, you will gain weight. If you are in balance, you will maintain weight, and if outgo exceeds income, your weight will drop. It's like your bank account. There are two things you can do. Improving your diet and exercise takes time, and it takes discipline.
Diets take time.
It takes time for your body to adjust to lessened food intake, and get around to burning off those inches. It takes more time for most of us to shed those trashy eating habits, like our addictions to hot fudge sundaes, milkshakes, pints of beer, french fries, and size huge pizzas. We all want to feel like life is bountiful, but overindulgence at the table is a dangerous habit, especially if you have diabetes. I suggest you start by making an inventory of your eating. Then, you and your health care team can construct a reasonable and workable meal plan.