You're right, I forgot that part! -- Can't understand why, I learned it in 1963, that's not so long ago.... Haven't sung it since around 1965.
I *think* it should read "e ad altro amor s'affida," not "s'offida." I believe it means pledged herself, linked her self, "affiliated" herself with another love. But at this late date, that's half memory and half a SWAG (Sophisticated Wild-Ass Guess). - Rita F