How do I get the real IP address when using reverse proxy + cloudflare?

[FuzzyJelly]

First of all, I've been loving Jellyfin and can't wait for more development and features in the future!

So I've been running my JF server locally for a few months but my significant other was interested in watching things when away from home, so I started looking into reverse proxies. I got it up and running with Cloudflare + nginx proxy manager fairly quickly but I noticed whenever I access the server, I only get the local IP address (172.17.X.X). Other than that, everything is running smoothly.

I tried adding lines to my nginx config through the GUI but nothing seemed to show the real IP (I tried using 'Custom Location', as well as the 'Advanced' tab) and I clearly changed too much between that and the JF network settings because I somehow locked myself out of JF and had to completely reinstall it. I got the basic reverse proxy set up again last night but other than that, my settings are completely fresh. 

I've attached screenshots of nginx and the only thing that is modified in JF is 'Allow remote connections' is enabled. Can anyone tell me what I'm missing?

JF: 10.8.13
Setup: Docker
Proxy: Nginx Proxy Manager
Additional: 

• Using Cloudflare
  
• Using subdomain (ex: jellyfin.example.com)