cannot access my website after updaing the nginx config file and doing OS updates

I am a total beginner with servers administration and Ubuntu. I am using Cloud66 to manage my digital ocean droplet. My website was opening normally today, then I have done three actions, which lead to my site not opening anymore on browsers with the below error:

ERROR
The requested URL could not be retrieved
While trying to retrieve the URL: http://www.sitename.com/
The following error was encountered:
Connection to 198.211.118.189 Failed
The system returned:
    (111) Connection refused
The remote host or network may be down. Please try the request again.
Your cache administrator is webmaster. 
Generated Wed, 11 Feb 2015 22:59:11 GMT by google.com (squid/2.7.STABLE6)

These are the three action I have taken today: 1- Added some lines to my nginx config file through cloud66 interface after the change I checked tafqit.com still working…no issues. (But I am not sure when the change of the config file takes affect? ) below are the lines I have added, please note that I have no experience but was trying to enable caching for my site…and found this code from a solution on the Internet.

location ~ ^/(assets)/  {
  root /path/to/site;
  gzip_static on;
  expires max;
  add_header Cache-Control public;
  # access_log /dev/null;
}

2- Accessed my droplet through digital ocean console and run update sudo apt-get update and sudo apt-get upgrade 3- Rebooted through the same Digital Ocean console using the command sudo reboot.

After the reboot the site is no longer accessible. What may be the reason??