I know this is beyond the scope of your question but you are at a very similar place like i was over a year ago.

For the reverse proxy you want ingnx manager and it will handle all of your reverse proxies just fine.

But what i really want to recommend is to change up that debian into proxmox,

Proxmox is a debian based efficient server OS. Basically every service you run now can Easily be run as its own isolated container with very little overhang.

Best of all there is a community for Helper script that will install entire services including Nginx but even nextcloud from a single command.

https://community-scripts.github.io/ProxmoxVE/scripts?id=nginxproxymanager