Hey guys! Im submitting my application for R2 tomorrow. Took the GMAT yesterday (had a cold and a fever) and did not do well on the quant and IR - embarrassed; on my practice tests I usually got around 710-720 and the actual test came out to be 650

... Not sure if I should retake it or leave it as it is; won't be able to retake until December 18th or so. I took 4 college level math courses - regular college math, stats and 2 semesters of calculus, and excelled in all of them - judging from my transcripts, I obviously know math. Does anyone know how the adcom acts in such cases? Do they typically let candidates re-submit the GMAT before making a decision? Should I retake it or is it going to be too late?
Also, a little confused about the instructions on submitting transcripts. I know they ask us to upload unofficial copies, but then do we have to send official transcripts by mail, or is that only upon request?