Cannot login after installing Monterey OSX except in safe mode

Think we may have discovered the Culprit from Screen Shot - Thank you that.

Sophos AV Software and perhaps the Cisco AnyConnect . Remove Both as per Developers Instructions.

Are there any AntiVirus, Disk Cleaner, Optimizers, Un-installers, etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation. The The Built in Security  is all that is required.

There are no known Windows-like Viruses in the wild that self replicate and affect macOS because of the underling UNIX  Foundation and Permission Limitation. 

Cisco AnyConnect - Commercial VPNs should only be used if Mandated by Corporate Head Office for working remotely. Otherwise - ones Privacy and Security touted by the VPN is suspect. 

Here's some food for thought: there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.  

There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   

Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.

There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is desshoigned solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  

Also, unless you're using a true VPN tunnel, such as between you and your employer's or bank's servers, they are useless from a privacy standpoint.  Read these two articles: Public VPN's are anything but private and Former Malware Distributor Kape Technologies Now Owns ExpressVPN, CyberGhost, Private Internet Access, Zenmate, and a Collection of VPN “Review” Websites. 

However, that being said one of the most respected contributors to these forums and a respected developer has reported favorable about NordVPN.  So it may be more secure than most of the other public VPNs. But generally unless required by employer, school or bank they aren't worth using.

Do you have apps installed which load helpers/ daemons on boot up. Things to avoid are anti-virus and cleanup-up apps. If you look at your login items from system preferences you can see what is loading and you can disable them before trying a normal restart. If you identify the culprit you can uninstall it.

In addition to login items, there are also launch agents and daemons. None of those launch in Safe Mode, and they could be causing the trouble you have when booted normally.

I would start by creating a new admin account, just in case we may need to do something with yours (a second admin is something that should always exist in any mac).

In your account, check the contents of the following folders:

/Library/LaunchDaemons

/Library/LaunchAgents

~/Library/LaunchAgents

To get to these folders quickly: in Finder, press Command-Shift-G and paste each of lines above.

Post screenshots so we can know what is there and what is more likely to cause trouble.

As Others has pointed out possible issue but added - How Much Empty Space was available Before attempting the Monterey upgrade.

Apple states " If upgrading from macOS Sierra or later, your Mac needs 26GB of available storage to upgrade. If upgrading from an earlier release, your Mac needs up to 44GB of available storage.

The fact the computer will boot in safe mode - still login issue - but will not in Normal Mode, could be an indication that there is not enough Empty Space on the drive to load while all the other Software active.

Safe Mode eliminate all Third Party software from loading and thus Safe mode will boot though not fully with Login issue

After-Market SSD ?? There are several other persons with After-Market SSD installed and the issue appears to be Monterey Requires an EFI Boot ROM flagged to the drive which it can not do to Non Apple Original SSDs