Hi Kaddyuma,
When these types of score drops occur, the two likely "causes" involve either something that was unrealistic during practice or something that was surprising (or not accounted for) on Test Day.
To start, I have a few questions about how you took your CATs:
1) Did you take the ENTIRE CAT (including the Essay and IR sections)?
2) Did you take them at home?
3) Did you take them at the same time of day as your Official GMAT?
4) Did you ever do ANYTHING during your CATs that you couldn't do on Test Day (pause the CAT, listen to music, etc.)?
5) Did you ever take a CAT more than once?
It's possible that you just had a "bad day"; but if we can figure all of this out quickly, then you shouldn't wait too long to retest. You'll clearly need to put in some extra work on the Verbal section, and that might mean investing in some new GMAT materials, but that section of the Test is just as predictable and standardized as the Quant section is, so you CAN train to score at a higher level.
GMAT assassins aren't born, they're made,
Rich