Sherlock comes back and immediately gets depressed when he learns what had happened during his absence. Mrs Hudson has been dead for some time (died of old age, plain and simple).
Lestrade was fired because of everything that had happened before Sherlock's fake suicide. He's no longer in NSY and gets drunk sometimes.
Molly no longer wants to see Sherlock after lying to people for so long and watching them falling apart, because she couldn't tell them that Sherlock was alive, and Sherlock didn't bother to inform them himself. Gradually, it made her feel disappointed in Sherlock so much that, if he needs her lab for something, it's best if he asks somebody from another shift, not her.
And John... John had mourned him for two years, but seeing Sherlock's cruel lies now, he's so disappointed that he doesn't even allow himself to look back. He moves on. If he's with Mary, he never lets her convince him to talk to Sherlock, and she accepts it.
Sherlock comes back, but it no longer matters. (Character's Death, Angst)
Lestrade was fired because of everything that had happened before Sherlock's fake suicide. He's no longer in NSY and gets drunk sometimes.
Molly no longer wants to see Sherlock after lying to people for so long and watching them falling apart, because she couldn't tell them that Sherlock was alive, and Sherlock didn't bother to inform them himself. Gradually, it made her feel disappointed in Sherlock so much that, if he needs her lab for something, it's best if he asks somebody from another shift, not her.
And John... John had mourned him for two years, but seeing Sherlock's cruel lies now, he's so disappointed that he doesn't even allow himself to look back. He moves on. If he's with Mary, he never lets her convince him to talk to Sherlock, and she accepts it.
Depression, angst and heartbreak, please.