tormented (or conflicted person, spec. one who is engaged in an inner struggle) n. agonist

[Boxer Bernard Hopkins] not so much a contrarian as a serial agonist who regards life as an unending train of struggles for the upper hand, [believing that] a life is best lived through a relentlessly calculated managing of self rather than the self-destructive fury of all-out aggression. (Carlo Rotella, “Bernard Hopkins, Boxing’s Oldest–and Most Cunning–Champion,” The New York Times, 10/31/2014.)

This word can also be a synonym for a person who is conflicted or anguished.