What happened to my Google SERPs?

Wow, just last month i was ecstatic because i made it to page 2 of google for ' las vegas foreclosures '.......and now i'm nowhere to be found!.....think i dropped to page 9 or something. But still, what happened? Maybe i should stop doing my own seo and just hire a SEO specialist huh? I don't think i'm the only one though cause i have read about a lot of websites going through the same ordeal the last few weeks.
On the other hand, i have crept up to like page 5 of Bing for a few keywords..... not bad:)