Hmmm.... how much time are you spending running? If you're averaging 9:23 min/mile(by my calcs) and you're walking sections of it too, it would indicate to me that you're running at quite a pace! Tonnes of people run slower than 9:30 min/mile pace without walking, so it suggests to me you may be going off quicker than your body wants to. I'd say on your next run, go out and run a lot slower, almost to the point where you feel you'd be walking if you went much slower, and then see how far you can manage. At typical easy running pace you should still be able to hold a conversation, if not, the chances are you're going too fast.
It might be worth you running as you normally do, and timing how long it takes you to complete the 1.4/1.6 mile run? That'd give us an idea of what pace you're running and a better idea as to whether it may be too fast or not.
I'm not saying it's definately the answer, but likely a number of things linked together, couple this with the eating/drinking regime you tried today and hopefully it'll help a little more :d
Keep us all updated - we'll get to the bottom of it soon
