“Mary is the Mother of Jesus.
Agree.
“Jesus is God.
Agree.
“Therefore, Mary is the Mother of God.
Disagree.
“If you deny that Mary is the Mother of God, then you deny that Jesus is God.”
Disagree.
The following is also a valid syllogism, which proves that anyone who denies that Mary is the mother of God also denies that Jesus is God:
Mary is the mother of Jesus.
Mary is not the mother of God.
Therefore, Jesus is not God.
All you have proven is that you have no clue what the science of Logic is about.