The best way to troubleshoot your setup is to test each bit by bit individually until you figure out where it’s gone wrong.
Try your qbit container without glutun. Can you download and seed a Linux iso from the same directory your current seeds are? If not, you’re probably looking at a permissions issue.
Next test your glutun container. Can you ping the tracker from the container? If not, your VPN isn’t set up correctly.
Lastly try qbit via glutun, if it doesn’t work it’s a port forwarding issue.
Good luck!
Do you have ssh access running on local network? If so, all you have to do is forward the port. I’d recommend exposing a non-standard port, also using keys rather than password.
If you don’t have your sshd running yet, it sounds like you need to read some guides to get a foundation, then come back with specific questions.