Test day is all that counts...

Here is a not so pleasant story on my gmat experience. I have dedicated the last couple of months exclusively to GMAT prep. My test scores so far:

MGMAT1: 700
MGMAT2: 750
MGMAT3: 720
MGMAT4: 740
MGMAT5: 750
MGMAT6: 770

GMATPrep1: 760
GMATPrep2: 720 (Tired and took late at night)
GMATPrep3: 760
GMATPrep4: 760

With this trend, I was surely expecting above 700. Infact targeted 750 and thought I might end up with 740. If anything I worried about running out of time on quant. However, I am extremely disheartened by the fact that I got 680 in my GMAT test today. Split Q50, V33
My lowest verbal performance so far. My very 1st diagnostic test and my lowest verbal on practice tests has been 37. I did not think I was doing this badly. The only off incident was that, the test administrator tapped on my shoulder during my verbal and said I was loud. I tend to mumble to myself, and with the noise cancelling headsets, couldn't hear myself...so didn't realize if i was speaking aloud. The tap surely jolted me. That said, I was surely disappointed to see this bad a verbal performance. I have no explanations or the slightest inkling as to what might have gone wrong. I am scheduling the test again in 2 days. I have exhausted all material and I will get busier with time. I do not want to lose touch with GMAT. God knows what would happen then!

Any advice for me from the experts?