It seems you, your website ranking have been droped form search engine or your keywords ranking has been fluctuate up or down for long distance. You should understand your website got penalty.
Just put this on google.com: site:yoursite.com. If you don't see your site anywhere, it is definitely penalized (de-indexed). Fast ranking drop is a sign of sandboxing.
if your site was already ranking for certain keywords and lost their ranking after recent algorithm update then you site is affected, however wait a few days for the algorithm update effects to wane off just to make sure