Do you know how your quant score compares to the averages at your target schools? It looks like your overall score is in Georgetown's range. I ask because if it's close then I wouldn't worry much more about it. I tend to think that the claim that the Q component is more important than the V component is over-stated, at least at the less Q-focused schools (MIT, Berkeley seem Q-focused).
So part of my point is that I think you need to think more about the other aspects of your application, namely the work experience. You seem to be taking the "holistic" view, which is good, but I'm not sure about the rationale for quitting work to focus on B school. While you appear to be making up for things with good, relevant extra-curriculars, I think some schools might view the lack of a job somewhat skeptically, particularly with only a few years prior experience. Are there opportunities to get some work experience in a field that interests you more? Can you turn the volunteer work into a paid gig where you can get more leadership achievements under your belt?
You seem like a strong candidate in terms of demographics, undergrad and extra-curriculars (and you have an impressive Verbal GMAT score), but work experience is probably the #1 criteria for evaluation in most cases. Generally I would say that delaying your applications to build up more work experience and related leadership is more valuable than further progress on the GMAT.
Just my opinion though. Best of luck!