Hi henrysgran and welcome to the forum,
I'm not surprised that you are confused. We expect to receive from our medics advice that (a) is sensible and (b) is good for our health. Unfortunately your doctor has failed you on both counts!
You have been told that you should control your diabetes with diet, and then told to eat all the things that will cause your blood sugar to rocket and will make it impossible for you to get the control that you need. Bread, cereals, pasta, rice and potatoes all contain starch and very little else. They are the worst possible things for anyone who is not being prescribed medication. In fact if your doctor had even bothered to read the British National Formulary (the doctor's "bible"), it tells him that before being prescribed oral medication, type-2s should be encouraged to reduce their blood sugars by a combination of reduced carbs and increased exercise.
If your doctor had said to you "you are allergic to nuts, they will make you very ill", and then added "so I want to to eat plenty of nuts with every meal", you would think he must have lost a few screws on the way to the surgery. Well, the diet he has suggested for you just proves that there are some screws missing!
Please have a read round the forum, particularly in the low carb and success stories threads, then ask away if you have any questions. We will do all we can to protect you from your doctor!