Guys i need help i get updated my iMac late 2015 to sequoia but it keeps on showing Tahoe update and i accidently pressed the update and it did it soo quickly

Guys, I need help. I updated my iMac (Late 2015) to Sequoia, but it kept showing the Tahoe update. I accidentally pressed the update, and it happened really quickly. After that, Tahoe opened, but only the wallpaper showed. I asked ChatGPT, and it gave me a solution, but I followed it (stupid me) and erased the HDD. I think I also erased the OCLP.

Now it’s showing the blocked sign with the URL: https://support.apple.com/mac/startup. I checked the website and followed the shortcut, and now it’s loading. Guys, please help me. What should I do after the recovery panel pops up?