Pete.
We are not allowed to diagnose on here so this is based on my own experience. How were you diagnosed in December 2009 ? Was it just your GP or have you seen a Consultant, an Endocrinologist ?
Are you taking any other medications, particularly those not Diabetes related ?
Has your GP ever mentioned Reactive Hypoglycaemia to you ? As you say your diet seems pretty good to me, there is definitely something else going on here.
Here is some information about RH......
Low blood sugar (hypoglycemia) usually occurs while fasting. But reactive hypoglycemia is low blood sugar that occurs after a meal — usually one to three hours after eating. Often, the cause of reactive hypoglycemia isn't clear.
Some researchers suspect that certain people are overly sensitive to the normal release of the hormone epinephrine, which causes many of the symptoms of hypoglycemia. Others believe that a deficiency of glucagon — a hormone that normally offers protection from low blood sugar — may cause reactive hypoglycemia.
In a few cases, reactive hypoglycemia may result from excessive production of insulin by the pancreas (hyperinsulinemia). Reactive hypoglycemia may also occur after stomach surgery or due to certain enzyme deficiencies, which may interfere with the balance between nutrient absorption and insulin secretion.
I think you need a referral to an Endocrinologist urgently and I wouldn't accept a NO from your GP.