For the MCAT generally the rule of thumb is that 30+ is a competitive score and over 32 is quite good. I think you have a good shot if you get a 30+ MCAT and around 40 hours of shadowing and 100 hours of clinical volunteering. Your PS should tell why you want to do medicine and should not be just because I cannot be a dentist. Tell your story but make sure you answer why you now want to practice medicine.
