Good evening, skydzntcare.
If you don't mind my asking, what was included in your breakfast? And how much water had you consumed the day before your hike?
The reason I ask is Heat Exhaustion (leading to Heat Stroke) and Hyponatremia can have very similar signs/symptoms. The difference is Heat Exhaustion patients need water; Hyponatremia patients need sodium (and, perhaps, other electrolytes). Bananas have hardly any sodium and neither does Vitamin Water (the Vitamin Water has some other electrolytes, but not sodium). The Clif bar does have some sodium, but not a great deal (maybe 6% of the "daily need" based off the 2,000 calorie diet standards - again, not a lot). It seems to me that if you had Hyponatremia the water and vitamin water intake would have worsened your condition. However, each person acts a little different when suffering Hyponatremia depending upon their level of sodium deficiency.
On a side note, Wilderness Medicine Institute (WMI) - a division of NOLS - puts together monthly/quarterly scenarios as part of its newsletter to its Wilderness First Responders (WFRs), WEMTs, WAFAs, and WFAs alumni. If you feel like sharing it, your story may be picked for a scenario and help certified first aid and wilderness medicine folks brush up on their skills. You can contact WMI here if you so choose to share your story: http://www.nols.edu/contact/wmi_comments.php
Glad to hear you recovered and lived to learn from the experience, as well as share your experience with others.