Glucose tolerance test question?

Okay so they kinda surprised me with an early test yesterday well I just check my results and it was 150... I told them I had a full subway sandwhich with white bread about an hour before but they still had me do it... could that have affected my results making me fail the test?? I'm worried now 😯 and I get extremely hungry and dizzy if I don't have something to eat every 2 hours so I couldn't imagine ever doing the 3 hour test.