Good decision to thumb the dive. The one time that I felt oxygen starved was after chasing a barracuda for a picture. I have learned to stop everything that I am doing. Hold still. Focus completely on taking long, slow breaths. I do a three count on the inhale and a three count on the exhale. I will continue to do this until the CO2 drops and breathing and relaxation returns to normal. It sounds like you were completely stressed from waves, weight and too much fun the night before. And one more thought - 8 to 10 off the back of the boat is bad news on a good day!