who get the engagement ring when a wedding is called off in Florida?

Ordinarily, where the man gives an engagement ring but the woman breaks off the engagement, the man can sue to recover the ring. In your case, however, you claim your fiance broke off the engagement and had promised you before this that the ring was yours "no matter what." In this case, an issue of fact is created as to whether the ring was a "gift." If he sues you to recover the ring I would hire an attorney in your area to represent you.