Macbook bricked ?

Hello! I am looking for help !
I wanted to move from Ventura to Sequoia. I followed this tutorial : https://www.youtube.com/watch?v=in5-3EjKFqA&list=WL&index=46&t=284s

I struggled to create the boot media, I just ran opencore legacy with sudo with the terminal. Then I installed Sequoia as mentionned in this video, my Mac didn't boot 4 times, it rebooted once, keep updating and finally booted on the recovery environnement waiting for an input. After waiting some minutes, I selected shutdown and removed the media. Now I have a crossed circle on my mac. Can someone help me, please? It's a macbook 12 inches from 2017-2018.