Word for a persistent fear of something actually leading to it being true [duplicate]

The situation you describe is an example of a self-fulfilling prophecy:

A self-fulfilling prophecy is the sociopsychological phenomenon of someone "predicting" or expecting something, and this "prediction" or expectation coming true simply because the person believes it will and the person's resulting behaviors align to fulfill the belief. This suggests that people's beliefs influence their actions. The principle behind this phenomenon is that people create consequences regarding people or events, based on previous knowledge of the subject.

That would make your first example sentence:

It was an example of a self-fulfilling prophecy.

but I do not know if there is a term for a person who frequently encounters this because of their character.