I wouldn't stress too much about your GRE scores. I believe (correctly I think) that the other pieces of your application will be much more important than 40-50 points on the quantitative portion of the GRE. I have been accepted into 3 PhD programs will full-funding and waitlisted at another. Two of these programs are in the top 25 in my field. My GRE score was 1140 combined (520 verbal, 620 quant, 5.5 awa). By all accounts, my score is not very competitive, yet I was able to earn a spot in top-tier programs with funding. If you do happen to get rejected by every school you applied to, I would be willing to bet that your GRE scores will not be your downfall, it will be another piece of your application.