What is the antonym of "luck out"?
You can say your luck failed, which doesn’t use it as a verb but still keeps luck in the sentence.
However, a nice alternative is struck out.
I'm fairly certain that in colloquial English to have 'lucked out' has the opposite meaning as it would in America. So in England the same phrase will mean to have been unlucky. There's a brief reference to this in Bill Bryson's book 'Mother Tongue'. As an alternative for both sides of the Atlantic, to be 'out of luck' sort of works but it's not quite as pithy. Hope this helps.