What could have caused me to breakout in a cold sweat, feel numbing sensation in hands and face, dizzy, hear buzzing sound, and turn pale white?

Vagal response: Sometimes when you are in an anxiety state or nervous about something , you can develop a vagal response. With this, you get sweaty, light headed, weak, anxious, pale, and cold. If you lay down and relax, this symptoms rapidly improve. This is not necessarily a problem, but if it keeps happening, more evaluation with your primary care md is warranted.

Merits evaluation.: Your symptoms merit a visit to your physician. The exam should include checking your blood pressure sitting and standing. Dehydration can cause your symptoms; if that's the problem, your blood pressure might be very low upon standing.