6 Months Ago I Blacked Out Behind The Wheel. The

6 months ago I blacked out behind the wheel. The doctors never really diagnosed what happened. Thought maybe my blood sugar level dropped. I am a diabetic controlled with medications, had quad heart by pass 2 yrs ago no problems, and high blood pressure also controlled with medications. Everything has been fine until just a few minutes ago, felt like was going to black out (while at work). Tested my blood sugars and was at 237 (my numbers have been in the 120 to 130 range). I'm starting to get worried what do you think?