Maybe your insulin regime is not properly matched to your food intake. This would help explain why your sugars are so high. What insulins are you taking and how are they dosed?
I think you should read up on diabetes and it's managements.
I would suggest a low carb diet as well. If you eat less carbs your body will have less need for insulin.
Ask for a referal to an endocrinologist, if necessary. it is very important to get blood sugars controlled to prevent complications.
I'M not sure..You didn't say if you were a Diabetic??? On a daily basis over 250 is not good. If you are Diabetic, eat less sugar, less carbs and more vegs, whole wheat breads, whole wheat pasta, exercise should lower your blood sugars,. However if you are like me on Insulin and constantly stressed THAT raises your blood sugars so find ways to help you relax and calm the mind and body. Lots depends on what you are eating??? Look up www.diabetes.org and you can learn allot on health, foods to eat, tracking your blood sugars and ways to lower stress etc.. Good luck.