Even though I sobbed through John ‘talking’ to Sherlock, this broke my heart. Because once you get past the fact that Sherlock is indeed alive you have to take in his expression.
He looks numb.
He’s been watching John, and he’s seen the pain he’s in, knows that the reason John is feeling this way is because of him.
But the worst part is that he can’t do anything about it. Because even though Moriarty is (presumably) dead, Sherlock knows that if he’s even hinted at being alive, one of Moriarty’s henchmen will be there to follow out their bosses orders. And therefore the only reason he stays away is because he knows it’s better for John, as hurt as he is, to believe he’s dead. All he can do is watch as his friend grieves at a distance.
Because a grieving John Watson is better than a dead one.
And just as John has reverted back to his military training, Sherlock has reverted to the cold, steeled, and unemotional facade he wore before he met John.
And that, is what breaks my heart.
And both of them are latching onto these old and familiar patterns of behavior in order to survive and cope with their respective grief.