Precarious
Part of speech: adjective
Definition: dangerously insecure or unstable; perilous depending on the intention of another
Example sentence: The world's my oyster. But it worries me, all this showing off about being happy. Life is so precarious, and I know terrible things can happen. At the moment, everything is happy.
Insecure
Part of speech: adjective
Definition: Not secure.Not comfortable or confident in oneself or in certain situations.
Example sentence: People gossip. People are insecure, so they talk about other people so that they won't be talked about. They point out flaws in other people to make them feel good about themselves. I think at any age or any social class, that's present.