The Shema is the statement of faith. The golden rule is different. Go look it up in the Jewish Encyclopedia.
The origin of the story “that which is hateful to you...” was an answer that Rabbi Hillel gave to a brash person who demanded that he be taught the entire Torah “on one foot.”
That that Christianity holds itself as more moral or loving by calling its credo “love thy neighbor” means only that you chose to highlight that difference. (they are anti-hero, we Christians are pro-love.)
It’s a relative ‘feel good’ however, as Jews say, viahavta l’reyacha kamocha, love your neighbor as yourself. From where did JC learn such a thing?