Hi there,
Thanks for your post. So while your background may be a little less common for b-school, that doesn't mean you can't make a case for why you need the MBA... and that will be very important for you since it may be less apparent than for some. So keep that in mind. You may want to think about schools that have more ties to the education world, such as Stanford (though huge reach especially without top GMAT score), Columbia, Yale, Kellogg, Ross, GW, Rice, Owen for example. It makes sense to give the GMAT another shot -- not much to lose by trying again! In fact now if for some reason things didn't go well, you can cancel the score, and the cancellation no longer even shows up on your score report with recent test administration changes, fyi. In terms of when to apply, I think it's best when you feel you are ready career-wise to make that change, and that you also feel you have relevant experience to bring to classroom discussions. Think about taking the GMAT again with a bit of prep first (if interested in top schools as you've mentioned), then check back in for some more feedback perhaps!

Keep us posted and good luck!