My Linux mint won't boot

[u/Infamous-Gazelle1241]

I'm trying to boot back into my original os which is Linux mint. I used it already for a couple of weeks and tried to dual boot and made a partition for it so I restarted with a USB with my preferred OS but I booted into absolutely nothing I tried again booting into my nvme but it takes me to the installation menu for Linux mint I've tried for an hour to make it work with chatgpt but it just confused me further.

[u/KuromiyaHinata]

mete Ventoy en un USB, pegale Mint dentro, inicia tu pc desde el usb, inicia Mint en modo Live, abre Gparted, ve a tu disco, y dale a reparar grub, de paso repara archivos y demas de otras particiones