Difficult to say why you dropped so significantly. Maybe your added pages are not fitting in the main topic of your business for Google. Without looking at it properly it is difficult to say anything to be honest.
Very difficult to say anything without looking at the data then to be honest. It could be another small Update from Google, since they have them almost daily, it could be an attack from the competition, it could be that most of your backlinks are banned by google, it could be that your competition does something better and so on. Very difficult to say without any data 😀