neptuli on "Site went down?"

Hi everyone,
I've been using wp for a while, but without any reason, the website i'm working on now went like this, http://www.julianemenier.com , just like when your internet is really bad, or as if the site was overload…I was just uploading plugin WP security, changing the settings for a couple minutes, checking the site,everything ok, and then this…I've undone everything but it still looks like this…
would you have any idea on what that might be?? I gotta say i'm lost on that one...
Thanks a lot !