Who cares who it was “truly” written and who cares if the word “homosexuality” isn’t literally in the Bible? The King James Bible, which was written in 1622, is the most commonly-used English language Bible and it’s unapologetically anti-gay (ironic, since James himself was gay).
And I call bullshit on the Leviticus part. Firstly because putting the young boy to death as well makes no sense and secondly because I would find it hard to believe that ancient Jews who had over 600 laws about what you shouldn’t be doing were just fine with the gay stuff.