If your Website is penalize by google then it don't show any index page or no link count by goole. Check site:url
it could be named as google dance, or whatever, but its quite normal. Your site is new, so google is putting it to the front of serp to check how people react on it. You should just keep on building your site, and google might get you back where you were, but that could take as long as 6 months. Another explanation is that google put you on fron beciause your content is fresh and new, so it got higher priority. Generally, no one can tell you what happens
Register with google and go to webmaster tools, there is an option where you can send a message to google (site reconsideration or something lite that), you need to explain a bit what happened and quite soon they shall get your site back in their index. I had the same problem once before, where site was out of googles index for no apparent reason, except that whole site was flash.
try to submit your website homepage in different search engine so that it can be indexed by different search engine.
be careful to do SEO to your site because google has change their algorithm. so many sites has de-indexed, banned and penalized by google