loving your enemies may be pointing out their mental illness in not accepting who they are...
Perhaps Jesus was quoting Hillel (110 BC-10 AD), whose teachings he studied, who was quoting Levititcus 19:17-18 “Thou shalt not hate thy brother in thine heart: thou shalt in any wise rebuke thy neighbour, and not suffer sin upon him”.
18 “Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbour as thyself: I am the Lord”.
Hillel was referring to fellow Jews, and the commandment was to advise the fellow Jew of his ways and allow him the chance to repent, but not take revenge yourself - that is the job of God. It is more akin to the saying “Hate the sin, but love the sinner”...God will judge all sin.