I recommend you sit tight and don't panic for another couple of weeks at least. When google goes through big changes like it is at the moment, its easy for sites to get lost.I see it often. Especially vulnerable, are sites that have had internal changes or have moved to a new host recently.Or perhaps the sites linking to you have, and you have lost the benefit of their backlinks. If you feel you need to do something, I suggest you try to obtain a backlink from a site that is still doing well, just to remind google of your site.
