Go back to basics; water, protein, exercise. You want to have 64oz of water a day, about 80+ grams of protein and at least 20-30 minutes of exercise every day. I weigh my food to make sure I stay at the 2 oz meals my doctor recommended. I eat the best quality protein I can get; chicken, fish, yogurt, cheese. I don't eat carbs and very little fruit. I walk around with my water bottle everywhere I go.
A good way to kick start your metabolism is eat tiny meals more often. I eat my 2oz about 4-5 times a day. I don't wait to get hungry; I eat about every 2-3 hours. This keeps the engine running.
Keep doing what your doctor has told you to do and it will come off. There will be stalls along the way, just stick to the program or amp up the exercise. You'll do fine.
Good luck to you.