Self-sacrificer

[…] they even willingly forfeit all the rest, and turn as it were Martyrs and Self-sacrificers to but so faint a Shadow or scant Resemblance of the first uncreated Perfection […]

1728, attributed to Daniel Defoe, The Memoirs of an English Officer, London: E. Symon, p. 186, After these Street-Exercises, these ostentatious Castigations are over, these Self-sacrificers repair to the great Church, the bloodier the better; there they throw themselves, in a Condition too vile for the Eye of a Female, before the Image of the Virgin Mary […]

1856, Amelia M. Murray, Letters from the United States, Cuba and Canada, New York: Putnam, Letter 23, pp. 281-282, Northern clergymen in Florida, Scotch ministers in the North, and bishops with dioceses each as large as all England; men devoted to religion, charity, and learning—self-sacrificers, fearless, incorruptible […]

It was a state of joy which only the self-sacrificer knows.

[…] I think self-sacrificers tend to burn out early; they haven’t taken care of themselves.