Do I have diabetes?

Hi, my name's Peter Sharples (mis-typed Peer Sharples when I signed up)
Three years ago, when living in Cyprus, blood tests showed high blood sugar. The doctor sent me for a diabetes test involving drinking two cans of lucozade. Two hours later, my blood glucose had dropped to fasting level. A few months ago other blood tests in the UK again showed elevated blood sugar, so my GP sent me for a diabetes test, and again blood sugar dropped rapidly to fasting level after the glucose drink. So, my GP didn't declare me diabetic, but said the test should be repeated after I lose some weight (It's work in progress!). Meanwhile I've started to self test with an Accu-chek Aviva Nano calibrated with control solutions. My fasting level yesterday morning was 6.4. Two hours after a very substantial breakfast it was 6.3. So, my question is do I have diabetes or not?

Thanks everybody - your answers were very enlightening and helpful. They give me options to follow.

Update: Having followed a suggestion in Dr. Mowll's video, I'm confused by the blood sugar readings I obtained: Here's what happened: Immediately before evening meal today, having not eaten anything for 3hr, my blood sugar reading was 5.1 mmol/l. I then ate a baked jacket potato weighing about 250 - 300g with a small amount of butter, about 75g grated cheese, some green beans, brocolli & sprouts and a glass of rose wine. After eating, here are the blood sugar readings. 30 min: 7.4, 60 min: 5.2, 90 min: 5.7, 120 min: 5.9, 150 min: 6.5. I'm wondering why the values drifted upward towards a second peak after a pleasing 5.2 value at 60 min. I'd be grateful if Dr. Mowll or anyone else could explain the results.

Thanks Indy51, that's reassuring. I just didn't understand why the glucose level would climb into the diabetic range after reaching a low of 5.2. In any case, I'm not paranoid about the situation: I know I need to loose 10kg and eat more protein & less carbohydrate.