Dehydration or something else?

something similar happened to me. last summer i was at an amusement park and i hadn't eaten or drank anything. i was in line and my stomach was hurting a little then my vision was a bit blurred..then it got dark and i blacked out and i couldn't see when my eyes were wide open. it was really strange but i was sweating a lot. they gave me water and food and that helped a lot. so i don't know if this is similar to your situation, but just make sure you eat breakfast and drink water to keep you going