New update in Google- I am really very frustrating

[Black Ninja]

I continue working on my one website http://www.websitedesigncompany.net.au from last 2 years. Its performing well in Google search. But suddenly, something has wronged with this website and all ranking has been destroyed, then I checked my Google webmaster account and there is no any issue in my Google webmaster account. I also checked robots.txt file and Meta tags, no follow and do follow tags etc.

My website ranking has completely ruined, Even my website brand name "website design company" now ranked on 12th position in google.com.au. I want to show my ranking difference here:

Keywords                                                                        16-Jan       18-jan
Website Design Company                                                   2             12
web design company                                                          4             25
ecommerce website design                                                8             n/a
catalogue design                                                               6              n/a

I have never done any black hat technique to optimize my website. I always work according Google guidelines. I think, my website penalized by Google. But I want to know the reason. Why? My website ranking has been down. I am really very frustrating. Please any suggestion.....

[Webhelpforums]

Unfortunately Google is now extremely sensitive to backlinks containing keywords that either are similar to the domain name or possibly also "money" keywords. (Penguin)

They also started penalizing EMD (exact match domains) which I think also covers domains with keywords in them to some degree.

If you happen to have lots of low quality article backlinks (even competitors could easily add these using Fiverr or similar outsorcing services) then Google seems (in my experience) to penalize pretty quickly. (Meaning negative SEO, in my mind at least, seems to be pretty easy)

I don't have much suggestions except trying to get rid of such links. But even so, one can never really now what exactly is causing an algorithm penalization (above mentions updates/algorithms won't show as warnings in Google Webmaster Tools)

[Black Ninja]

Thanks "Webhelpforums"for your reply
I think,  you are right. But every keywords (A to Z ) has been down.  I have never worked on lots of keyword, but these keyword also has been down. Well, I am trying to remove all keywords based link (anchor link). I have also suited a mail to Google from my Google webmaster account and still awaiting Google answer.
I know, nobody know the exact reason of penalized. But, What can we do in against of Google?