Yours is a somewhat complicated situation as you have already done a great deal of prep. Here are a stream of thoughts and questions:
Where you averaging 620-650 on the GMATPrep CATs taken under official conditions? If so, you had a bad day on the official test to drop 60 points. More realistic CAT practice is definitely called for.
Is your goal score still 700? If so, 3 weeks is probably not enough time to get there.
Running out of time is obviously not ideal because you guessed and missed several questions in a row at the end of your sections. You need more pacing practice on problem sets and sections.
You also need to boost your IR score as a 4 is on the low side. Did you use the
MGMAT IR book for that? It is good.
As for your plan of attack, you have a fair amount to work on. I recommend my guide to the big picture of GMAT prep:
GMAT Clarity. It will ensure that you are doing all the little things right, which is really important because you have completed a great deal of prep and still need to boost your score much further.