Brewer's: Nail in One's Coffin
To drive a nail into one's coffin. To shorten life by anxiety, drink, etc. Topers call a dram “a nail in their coffin,” in jocular allusion to the teetotal axiom.
Care to our coffin adds a nail, no doubt; But every grin so merry draws one out.
Peter Pindar (John Wolcot): Expostulatory Odes, Ode xv.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894