My xcode installation was working fine. then the cpu heat/fan controller malfunctioned and the fans were off then all of the sudden the fans went full blast and my mac shut down and restarted. now I have to reinstall Xcode.

Xcode is not in a normal .zip file. It is in a .xip file. They are nearly identical except for one minor detail: .xip files are signed for integrity. The advantage is you are guaranteed to be downloading Apple's Xcode and not a fraud trying to get access to your computer. This is likely the cause of part of your problems, along with Xcode's whopping 17+ GB for an app. The xip has to first verify the xip integrity which will take a minute since the xip is pretty large. Then it has to unzip. The xip is probably packed tight so it will take a while. You can read more about the .xip file type - https://en.wikipedia.org/wiki/.XIP on Wikipedia. It's interesting.