The word used in this context is most likely ‘vice’ What are bad habits that is prevalent?

The Cambridge Online even gives an example sentence that is similar to the first example you have given.

vice noun (FAULT)

C2 a moral fault or weakness in someone’s character. Greed, pride, envy, and lust are considered to be vices. I am not a hater but my vices are cigarettes. My one guilty choice is chocolate.

Is it really bad to be insecure about what others think?