site disappeared

[vbsaltydog]

I have had a site up for about a month or so now and when I searched for the sitename minus the www and the com it showed the home page and one site that had a link to my site in the results. Last week I changed much of the text to add more occurrances of targeted keywords, added meta tags to keywords and description and changed the site's title. When I searched after making these changes I noticed that my home page was no longer returning in the results and only the site that was linked to me was a result. Then searching a few hours later there were NO results! Even the site that was linked to me failed to show in the results. I did a search for site:mysite.com to see if I was indexed at all and the results were no info available.
Have I been blacklisted? I have already asked google with no results as of yet. Any advise from the seasoned pro's here?