They're really, really, really different and are rejected by all real Catholics and Protestants (and Orthodox).
Define, please.
Antinomianism is defined as the doctrine or belief that the Gospel frees Christians from required obedience to any law, whether scriptural, civil, or moral, and that salvation is attained solely through faith and the gift of divine grace. It is the belief that moral laws are relative in meaning and application as opposed to fixed or universal.
I never said that, or implied it!