Reschedule/Cancel GMAT

Well if your goal is a 680, I do think that it would be a stretch to attain that score or better on test day on Sunday. The GMAT prep tests are the best estimate of how you will do on test day. It is generally recommended that you spend at least 2.5-3 months on studying to reach your full potential, and this would include 15-20 hours a week of studying plus numerous practice tests.

The fact that you didn't know what an integer was makes me believe that you are still lacking some fundamentals. Generally it is very challenging to get into the 650+ range consistently without REALLY understanding fundamentals. And without fundamentals it will be impossible to reach your top potential. With only giving yourself 1 month of prep, I'm sure your trying to rush into the most challenging concepts and questions, but without that basic understanding your going to have challenges.

If you are not applying this year, I would recommend that you stretch your studying out to a total of 3 months. In those 3 months you should dedicate significant free time to the GMAT. With how much you have going on (moving, intership, etc..) this may be a very challenging time in your life to reach your full GMAT potential.

Please read the following post to show you the extent of recommended studying: gmat-study-plan-start-your-gmat-journey-80727.html I spent 9 weeks and went from 570 on diagnostic to 710 on test day. BUT, I dedicated myself to 2-4 hours on every weekday, and 5-6 hours on each weekend day. The GMAT will be very challenging if you try to rush it. The GMAT is based solely on how you do against your competition, and your competition is FULL of dedicated individuals.