My website went from #3 to the last page of Google

Hi,
my website was ranking #3 for my main keyword in Google since December.Yesterday I discovered that from #3 it went to the last page of the results,and I haven't made any changes.
What do you think I should do?Contact Google about it or just wait?

ps.All my pages are still indexed.

 

Same here :S
Google still visits my site, only the amount of visitors that come from google went from 900 -> 40

All my pages are still indexed as well.

Anybody?

 

Are you sure your pages did not end up in the supplemental index?

 

Google performs data refresh regularly to determine the content relevancy of your pages. Most probably you may have lost quite a number of significant links from the external sources.

To verify this problem, you need to keep monitoring your Google sitemap account. You can also refer to my latest article, The Importance of Google Sitemap Account

 

Yeah but even if I search on my domain name (without the tld), I cannot find my site. Before, I always was #1...

 

How can anybody answer questions about why your sites are not ranking well when we don't know the url?

 

Can I at least contact Google and ask if I'm banned or something like that?
How can I contact them?

 

You can ask them but they are unlikely to answer. If you are still in the index you are not banned.

 

Just wait around and see what happens, this often happens to alot of websites. Happens to me occasionally too, but if things don't return to normal soon i'd be worried and get back to work! hehe.