There best thing to do at this stage, is to not stress. With less than 7 days to go, if you panick, you'll just kill yourself on the test day.

Just treat it like a normal test experiene and learn from it. It looks like based on your results you might have to sit it again. Most people sit it more than once so it's expected. So go in with the expectation you will have to sit it a couple more times. Treat this as just another test. You'll be surprised how your mindset changes when you realise you have to sit it more than once.

As for what you can do, it's really hard to say. You didn't give us any details besides your overall score (you baiscally told a cop the guy chasing you was around 170cm...how is he suppose to help you?). Perhaps write a debrief once you're done, and people will offer some suggetions.

I would consider retaking the GMAT Prep tests. There will be a couple repeats, but probably not that many. Sometimes the MGMAT CATs can be out of whack.