Antigone suffers from something many people of our generation suffer: reckless entitlement. Being the daughter of the former King and Queen of Thebes made her the royal princess. As the anointed princess, it can be inferred that her life was relatively easy, until her father was deposed.
The feeling of being entitled to having things her way actually runs in the family. Her grandfather and (grand) mother learned that their son Oedipus would kill his father and marry his mother(them). In an attempt to determine their own fate, they decided to do away with young Oedipus. As fate would have it Oedipus escaped death and grew up; he too learned of this fate and attempted to change it. We know how it turned out: fate won.
Later, Oedipus becomes a prophet when he predicts his sons’ deaths. Antigone then attempts to alter fate by telling Polynices not to fight Eteocles: fate won. In this: Antigone sees first-hand that changing fate is a non-option. (Along with seeing it second-hand in the case of her father Oedipus’ life, twice, once by his parents and once by himself.) I think, however, Antigone knew she could not change the fate of her brothers dying at each other’s hands, attempting to was important though.
This once-princess now knows she is unable to gain control over her destiny in the way she would like. For someone used to getting things the way she wants, this is a difficult concept to wrap her head around. Herein lies the tragedy: no matter how Antigone tries, she cannot control things that are beyond her. She is opposed to life because of the aspects she cannot control.(1) She is born in and of shame to incestuous parents. (2) Her family looses power. (3) Everyone in her family except her sister and her is dead. This is fate, although they all tried, nobody was able to alter(control) their fate.
Antigone knows she cannot change her fate. What she can do, however, is control her death. Creon sentences her to death, yes, but she kills herself before the sentence was fully executed. Not even Creon, the one who sentenced her to death, could prevent her from dying. (Her power over the state, the state could sentence her to death but it could not force her to live.)
The ultimatum she poses is childish. Nobody cares about the cries of a has-been, hence her cries often fall on deaf ears. Everyone faces the prospect of death. As much as Antigone would like to pretend her situation is truly abject, she is no worse off than anyone else (in fact, probably better). To commit suicide because one feel’s the cards they are dealt aren’t good enough is a pathetic example of self-pity. Suicide is the most selfish thing one can do. Antigone committed suicide because she couldn’t deal with not being in control.