Why Sherlock broke the coffin in anger

 (Sherlock meta by mae-jones)

Q: Why do you think Sherlock broke the coffin in anger TFP? [...]

A. [...] Sherlock and the coffin smashing - well, why does anyone break anything? It’s a release. He had reached a breaking point and needed to inflict his rage on something.

If he were enraged at Eurus, he would probably have smashed the focus of his rage, ie/ the television screen or the cameras. No, this was anger and frustration directed at himself and in that moment, the coffin represented everything he had failed at. He had failed to anticipate getting himself into this conundrum, to deduce Eurus’ true intentions of the game, to protect Molly (even if she wasn’t ever in real danger), and most of all, he had failed to protect his heart. Thus, smashing the coffin was an attempt to make it all ‘go away’.

What he realized shortly thereafter as he slunk to the floor with shaking hands, is that out of sight does not mean out of mind and an idea once it takes hold, it cannot be destroyed. The vivisection he referred to, was the extraction of something he had thought didn’t exist - his capacity for romantic love.

Eurus proved to him it did.