Hi and welcome,
There are 2 main diagnostic tests for diabetes. The primary one is an HbA1c. This measures your blood glucose over the previous 2 to 3 months, giving a very rough estimate. The second is an oral glucose tolerance test, where they give you a large glass of glucose (Lucozade normally) then test your reaction to it after an hour and 2 hours. That tells them how well your own insulin is working.
Perhaps you could tell us what your test results were? If you don't know them then you need to find out. You can either see these on-line if your surgery has this option (all surgeries in England were supposed to have done this by April 2016 but some are a bit behind) Or you can ring up and ask for a print out. It is important for your future control that you get these.
HbA1c under 42 is non-diabetic
HbA1c 42 to 47 is at risk of diabetes (known as pre-diabetic)
HbA1c 48 and above is diabetic
Are you on any medication for diabetes and if so, what?
Before we try to help with your diet properly we need to know!
PS Diabetes won't go away in June. A suitable way of eating is for life, not a few months!