What's a word for someone who needs to always be flustered about something? [duplicate]

Solution 1:

Near-synonyms are plenty, but "captious" is the word you are looking for. https://www.collinsdictionary.com/amp/english/captious

Solution 2:

How about-

glass-half-empty person

used to refer to an attitude of always thinking about the bad things in a situation rather than the good ones:

https://dictionary.cambridge.org/dictionary/english/glass-is-half-empty