Page disapeared after installing sitemap plugin

I installed Google Sitemap XML by iTx Technologies and now my site has disapeared when i do a google search.

When I go into Google Webmaster Tools > Crawl Errors it shows my URL as http://www.wolvestrees.co.uk/www.wolvestrees.co.uk, 404 Not Found. My website is http://www.wolvestrees.co.uk, should this be the URL and if so how do i change it on Google Webmaster Tools?