Few things here.
First this might not be the same MAC as previously- a new infection is more likely, so sensitivities might be different. It’s good that you’re getting them checked now but they should also check for amikacin to see whether it is an option to add Arikayce- usually at the six month mark if you haven’t responded to the standard Big 3
The side effects of Arikayce can be tough initially but many of us have had good responses. My cultures cleared at two months after it was added.