The words "discard" and "impetus" are correctly used, but they might sound a bit formal. In everyday language, simpler alternatives like "get rid of" and "push" might sound more natural. However, "impetus" is fine if you're aiming for a slightly more sophisticated tone. "After having plastic surgery, she felt it helped her get rid of her insecurities and gave her the push she needed to try new things and leave her comfort zone." Discard: It means to get rid of something. "Get rid of" is a simpler and more natural way to say it. Impetus: It means a driving force or motivation. "Push" is an easier and more everyday word that conveys the same idea. So, while "discard" and "impetus" are correct and natural in formal contexts, using "get rid of" and "push" makes the sentence sound more natural and conversational.

I don’t think ‘discard’ is the best word here and the sentence has other issues. Having plastic surgery eliminated her insecurities and gave her a much needed impetus to leave her comfort zone and try new things. To give someone an impetus To give an impetus to someone ‘Discarding’ is deliberate. It can be used figuratively as you have but it would make more sense if you were talking about someone who didn’t just have plastic surgery. Everyone around her was having plastic surgery done, but she was able to discard her insecurities by coming to understand their true origins.