Ok, so, Sherlock took drugs on the plane and he entered his mind palace set in Victorian London, he took drugs in that section and went into his mind palace inside his mind palace set in the present day and then goes to the waterfall THEN wakes up properly, the replace body happened earlier! Moriarty died early, the waterfall was from the original books, its symbolic from his mind palace, Moriarty does not have an army of women, he put Moriarty into his mind palace where he was solving a separate case in his mind! OH MY GOD! Moriarty is dead, he shot himself, but people are pulling strings to make it seem like he is still alive with the "Did you miss me?" piece.