Major Variation in GMAC Practice Tests/Test Coming Up/Very Concerned!!

To say I'm worried would be an understatement.

My test is around the corner on March 3 and I'm not sure if it makes sense to reschedule now or retake if needed. The situation is dire and I'm freaking out for a good reason as you'll see.

First GMATprep taken Jan 8, 2018 - Scores: 480 total, Q: 26 V: 31
I DID NOT finish the quant section and left the last 13 questions unanswered because I was under the impression that unlike the real test, It wouldn't time me out unless I was finished. Up to this point, ALL my preparation has been Quant meaning I took the Verbal section completely COLD.

Assuming the fact that Verbal would be my strong suit and that I left 13 questions blank on quant, this score didn't really surprise me. Since then, hours of studying continued except this time, instead of entirely focused on quant, I allocated a small portion of time on verbal preparation.

Second GMATprep taken Feb 12, 2018 - Scores: 400 total, Q: 22 V: 23
This time, I finished all the questions on Math and I seemed to be getting the same level of difficulty as last time but got a much lower score. The main difference that jumped out to me is that previously, I got the first 4 questions right but this time I got the first 4 questions wrong. Any explanations for this variation in quant?

As for Verbal; I'm at a complete loss for what happened and how to move forward from here. The level of difficulty seemed very similar if not more difficult this time around. Which score is a more accurate gauge of my ability? How can my score go from 60th percentile which was taken completely cold to 30th percentile? Why isn't there more of a correlation in scores here? How can there be this large of a variation if I tried harder, studied more, and still got this large of a drop?

Any and all suggestions as to what happened and how I should plan my preparation moving forward would be greatly appreciated.