Is it possible to loop a 360 degree YouTube video offline? I want to put a 360-degree video from YouTube downloaded offline and uploaded to WordPress so the user can immediately view a VR/Google Cardboard split-screen vid (no VPN required). The video would be a continuous loop and act as a "simulation" of an environment. Also, there would be the same capabilities of moving the phone around/gyroscope effect to view the video from a web browser.
You can use marzipano which will provide all the code necessary for the viewer and provide you with a Javascript API for customization. 

A quick Google search found me this Wordpress plugin which claims to do what you want as well.

Honestly, what you're asking is quite complicated. If you can't do it on your own using the tools linked above, I suggest you hire a web developer to do it for you.