You do not need to retake the MCAT since 510 is at or above the median for all DO schools. If you increase your GPA to 3.25 you could receive interviews at these DO schools so apply to all of them:
ACOM
ARCOM
BCOM
WCU-COM
LMU-DCOM
UP-KYCOM
MU-COM
WVSOM
VCOM (all 3 schools)
UIWSOM
NYIT-Arkansas
RVU-Utah
LECOM (both schools)
Where is your state of residence? You may have a chance at your state public schools depending on your residence.