First, Jesus is God.  

Second: If we take Jesus command literally--then we cannot refer to our earthly Fathers as Father or Dad.  Jesus also told us to call no one our teachers.  This means we cannot call our teachers teacher!  

Third: "He who sees me [Jesus] sees the Father."  He who looks on the priest sees Jesus.  He who sees Jesus sees the Father.

The role of the priest is to make present the mysteries of redemption through the celebration of the Sacraments.  Because the Sacraments, in particular the Eucharist are spiritual sustenance, the priest is providing for his people as a Father does.  That is why a priest is called "Father."  Biological Fathers provide for their off-spring, priests provide for their spiritual children--with the spiritual things of heaven.  

This is not rocket science.