Can you imagine how enormous guilt Sherlock must have had when he said “let him do what he wants, he’s entitled” after John had beaten him to a pulp, when he was lying there in blood, and John was looking at him with anger, blaming him for Mary’s death. Can you fathom how worthless he must have felt, like a piece of trash, letting John kick him repeatedly and not even trying to avoid punches. And yet, staring at John apologetically, Sherlock was crying over his friend’s loss, feeling so absolutely unworthy, as the one letting John down and causing his pain.