This video addresses many of the concerns of hosting stuff in public, and details a way (and some tools) to do it relatively securely. (There's always a risk there'll be a zero-day vulnerability in a web application like Jellyfin, but you can mitigate against them if you use the right strategies/tools, and you're vigilant enough.)
Since you're on cgnat, you can set up Pangolin on a VPS, or Tailscale-->rinetd-->Tailscale tunnel, also on a VPS. (Apparently frp is another similar solution, with p2p proxying.)