HI Cat, it’s really BS:madat: that they copied your content, but that’s not the reason your site dropped.
Is your content unique? Did you write it? Copy parts of your content and google it using “”
If your website comes up first, then google knows you were the first one, and he treats all other websites as they would copied it from you.
About your website dropping, where did you bought the last links? Was the website about the same thing that your is (content wise)? Google robots are getting better and better.
PM me if you want to know a bit more about it.