In this situation I would advise you to trace your domain following the steps below:
1.1) Please open the Windows start menu and type cmd it the 'Run' section. Then you will see the Windows console.
1.2) Afterward please initiate the following command in the console: tracert your domain.com
Then you will see the exact place where the connection to your site is blocked. Afterward please contact your Internet Service Provider for assistance regarding this matter.
You are able to see your IP address here:
Video tutorial regarding this procedure is available here:
If you have any other questions or problems, please let us know.