Hello , something happened to my site 2 days ago .It was ranking on page 2 for its most competitive keyword (domain name)and now its not available at all . now it only searches for some categories on pages 15-18 but the main url is out. while i was bookmarking my site 2 days ago in a few major bookmarking sites i also bookmarked on google (dont know why) and in my webmaster account i resubmit my site-map . nothing else . can this be the cause or i just got penalized by google for something.
can someone please tell me , i worked hard to get to page 2 and now its all gone. is there any way i can check why penalized and what to fix .