The worst I did is wanting to replace the WAN interface on my Opnsense router. I didn’t check properly and replaced my LAN interface instead, rendering the router inaccessible and fucking up my network. Luckily, its a VM on proxmox that was still accessible from IP. I just opened a console to the VM and found out that the whole configuration is in a file. Also, a copy is saved with every configuration change. I just found the right one to restore and voilà! My network was back up.