I accidentally deleted the Mac OS

Since I can’t access any of that information, I only know that the computer is an iMac, and the version is High Sierra 11 or 12.

After spending hours trying to get bootcamp to work, I started to install Windows 10. Unfortunately, the partition was in the “MBR style,” so I had to convert it to GPT. I followed a video‘s instructions, and then I ended up deleting the entire Mac partition with the entire hard drive dedicated to the Windows. Even worse, when I try to use the Windows partition, the Windows logo apears for a minute and appears the load, and then the screen turns black.

Basically, I don’t want to get rid of the Windows partition because I spent so much time on it, but it’s not working anyway. I also have some files on the Mac partition that aren’t really important, but I’d rather keep them. I was planning to try to recover it on Windows and the reinstall the Mac OS, but since Windows isn’t working, that plan is out of the window.

Is there any solution that involves recovering some files, keeping/fixing the Windows partition, and reinstalling the Mac OS?

I’ve tried booting into Recovery Mode. When I tried to use a Time Machine Backup, which it said existed, it just keeps loading and trying to find it. When I try to make a new partition with Disk Utility, it fails. Even when I try to reinstall the Mac, it fails. Besides the giant Windows disk, there’s two more disks named disk0s1 and disk0s3. I‘m really not sure what they are.

This seems like a giant request, but I appreciate any help at all.