Why do my keywords drop so quickly??

Hey all! I'm currently managing a news website that focuses on internet culture and trends. Before Google's update last week, I had a couple of articles that were ranking in the top 3 search results on Google for some high potential keywords—all I had to do was to update them every once in a while to make sure they remained timely and had more information than other articles. Since Google's update, we first dropped for all those keywords and in order for them to not drop below the 5 top search results on Google now I need to update all those pieces a couple of times a week (and still our organic traffic has gone down massively). Has anyone got any tips to share on how to update keywords and pieces? Any dos or don'ts that I should know of? Help would be greatly appreciated!