Welcome to WebmasterWorld Guest from 188.8.131.52
I can't even find Google Support, as all I am getting are their General Help pages.
Somebody PLEASE advise me on what has gone wrong here, as my site was formerly the most popu8lar site in its subject on Google search,
There are so many possibilities that it's hard to mention them all - but have a look through the Hot Topics area [webmasterworld.com], which is always pinned to the top of this forum's index page. You may get some ideas that way on what to research.