You are doing a Fullbright; you have a very good shot. When you return, take a couple of post-baccalaureate classes in community college or at a college nearby, as they will add to your UG cGPA to get it above the 3.50. You have to apply for entry in summer 2019, and once accepted, you might consider (or not) to defer one year at a single (preferred) school. The rationale for deferral must be very good as it needs to be approved by the Adcom.