Hi viper1991,
You've defined a big issue in your Test Taking - silly mistakes; now you have to define WHY those silly mistakes are happening and FIX those problems. For most Test Takers, the cause is not taking enough notes, not labeling your work, doing math in your head, etc. You mentioned the silly mistakes in the QUANT section, but what's going on in the Verbal section? Why are you getting questions wrong in that section?
I have a few questions about these CATs:
1) Did you take the ENTIRE CAT each time (including the Essay and IR sections)?
2) Did you take these CATs at the same time of day as your Official GMAT?
For these last few weeks, I suggest that you invest in some NEW CATs (re-using old CATs is NOT realistic) and focus on the precision of your work. Little mistakes KILL Test Takers. If you're making too many little mistakes, then a 650+ score is just not going to happen.
GMAT assassins aren't born, they're made,
Rich