Welcome to Flyertalk and welcome to the BA forum armanicat, it's good to see you here.
The crucial question here is whether you made this on one reservation, or two with the Italian flight separate from the USA flight? That makes a big difference in terms of outcomes.
This forum has a Dashboard and so general advice on Timetable Changes can be found in that Dashboard. This is a routine process, there have been a few other threads in this area in recent days, and depending on the specifics various remedies exist.