My website keyword is going down rapidly. Many keywords ranks well for long time but suddenly today morning i saw that they ranked poor. this is harsh to accept me, how it happened. Please suggest me best idea to out this.

When google algorithm update so some bad effect on website.

It is not uncommon to see fluctuations in keyword rankings for a website, this can happen when Google publishes another update, or if link building is no longer as consistent as it once used to be. I would suggest keeping a sharp eye on the latest news from Google, and keeping link building consistent to keep the ranks high.