The only way you should do a masters is if you feel there are gaps in your scientific knowledge that are an issue (you never took genetics, immuno, anatomy, phys, etc...), otherwise you don't need to prove anything academically. Make the most of your job experience (do something healthcare related). Definitely spend time with interview preparation and school selection research. Both will help a lot.
The masters would be a huge waste of time and money for you. Your gpa is fine, so move on to the other part of your app that are lacking. Consider an MCAT retake. Improve EC's. Try to get a new LOR from work or something. Re-write personal statement.
