Big Sur stuck during installation. Tried everything.

Sorry for the problems you are having. I have some suggestions that may help resolve the problem. I am guessing that the reason you are unable to successfully install your operating system is because the installer became corrupted during the download. Put the installer file, if you still have it, into the trash and do another download. (If the installer file is still there, it should be found in the Applications folder.) If you were using Wi-Fi to do the download, don't. It's too much data for Wi-Fi. Instead, you need to use an Ethernet cable directly connected to your modem/router. If necessary, temporarily move your computer to do the download. And during the process, stay off the internet. If you are unable to directly connect to the internet, then be prepared to do multiple Wi-Fi downloads until you get a good one that loads. And allow each download to fully complete, which can take up to an hour, more or less, plus another 45 minutes or so for the installation. Continuing to attempt to reload the original doesn't work and as long as the original file still exists, you very will be unable to do another download. Good luck. I hope it goes well.