Do you think it's worth writing a personal statement/optional essay explaining why my quant scores are so low? I'm really very concerned that they'll not want to admit based on that. I'm not sure how to put this, but I'm betting that there are a lot of other white american males that are applying with higher quant scores.
As Jon pointed out, you would be better without retaking it. The only reason I say this is because, you will compromise other parts of your application.
If you retake your GMAT on 24/25 Dec. you will be left with 10 days to write essays, talk to recommenders, fill in online application, collect your documents etc. And all this during the new year.
All your concerns are genuine. Bluntly speaking, yes your quant score is low and you know that for yourself.
What you can do: If you are hell bent on applying this year and want to apply in more than 1-2 schools, start with your applications right away. Address the quant score in your optional essay and the steps you will take to enhance your quant skills (some class/online course etc.)
Saying that, there are may people who get in with that score. Your overall score is pretty good!
If you can delay applying a year (very unlikely:)) or you feel you have a great story and might have a good shot in R3 then do retake your GMAT.
There was a very recent vid titled "should I never apply to R3" as part of 1000000 posts celebration. you may want to go through that.
Good luck with your apps.