I am currently an OTS but have been rejected from a previous cycle. If OT is truly what you want to do and you feel that the calling is affirmed, then I wouldn't give up. It is getting increasingly competitive. I reapplied and tried to use that year to better myself in areas of weakness. Venturing to applying more schools which you didn't consider before may also be an option. Everyone says the hardest part is getting in to a school. GRE is an easy filter for school to determine more qualified candidates but I know that it is not the only determining factor. Schools that conduct interviews and want to get to know the person face-to-face usually be less dependent and more forgiving of lower GRE and GPA scores.