From your score, it looks like verbal is the issue for you.
First - relax! There are people who have gone from 500s to 700 or 700+. You CAN do it too! You seem to have a good base on the GMAT Quant concepts. So concentrate more on the verbal this time and retake the test in 1-2 months.what books did you use for Verbal? I think the
MGMAT SC book is very good. I also liked the
MGMAT RC and CR books but these are not as comprehensive as their SC book. did you do all the OG problems? what were your practice test scores?