So basically my iMac was being extremely slow for the past week so I decided to reset it. I put it into recovery mode and went into Disk Utility and deleted Macintosh HD hoping to reset my mad. Now when I am in recovery mode and I go into ‘Reinstall macOS’ there is only one disk and it is locked. Here is an image of the locked disk when I try to reinstall MacOS. And I have also attached an image of my disk utility and as you can see there is no longer a Macintosh Disk and I don’t know what to do please help and when I restart my Mac it automatically sends me into recovery mode.