Gtown is generally good for getting its SMP students into other schools. The stats, last I heard:
180+ SMP students per year
15-20 get into Gtown
90 get into *a* med school immediately after finishing the SMP
another 54 get into *a* med school the year after finishing the SMP
SMPs like Tulane ACP/EVMS/Cincinnati/Temple, which have very strong same-school admissions, would set you up to not need anything other than a strong SMP performance. If you were doing one of these programs, you could "get away with" not taking the MCAT again.
Not so for GTown. As I think you suspect, you'd be spending $50k+ and still have to retake the MCAT, most likely.
That said, I don't think you should dive back into MCAT prep. Take a break. Maybe look into doing something like the Peace Corps, to get you away from school for a while. If you still want to go to med school on the other side, then you'll be rested & ready to go.
Best of luck to you.