Ultimately this isn't an EC2 nor self signed certificate issue as your certificate is good. It's important to use browser debug tools as they can often help you with the issue. For example, in Chrome I get a bunch of
roshiclips.com/:1 Mixed Content: The page at 'https://roshiclips.com/'
was loaded over HTTPS, but requested an insecure image
'http://i.imgur.com/0zWOURf.jpg'. This content should also be served over HTTPS.
and a few:
roshiclips.com/:1 Mixed Content: The page at 'https://roshiclips.com/' was
loaded over HTTPS, but requested an insecure video
'http://nba.cdn.turner.com/nba/big/video/2017/04/09/8669b068-3544-4cac-a863-58596304dba2.nba_1355868_1920x1080_5904.mp4'.
This content should also be served over HTTPS.
So I'd start by making sure everything is loaded via HTTPS. You've also got a few other issues with JavaScript and with a call to a websocket but those won't break the SSL part, just the operational part.
For reference, in Chrome, I went to the menu then "More Tools" -> "Developer Tools" to see the console. This showed me the warnings and errors.