Need Help to modify VM config

Hi

i have a problem since this week end. i cant log in to my fedora VM anymore. The problem is that i have made my VM boot at login and the network is not working (i use gpu passthrough to connect in local direclty).
I try to use a Live USB stick to mount my LVM volume but (pve-root partition) but in /etc/pve there is nothing in there.
How can i find and change this config file ?
on the login screen of my VM i cant access to the TTY console to connect to proxmox.

Any suggestions ?
Thanks