PROBLEM RESOLVED!!!!!!! I fixed my issue and I'm replying to this old thread because its the first that pops up on Google.
The fix for me was removing a USB flash card reader. When nothing is in the reader, it still shows 2 hard drives under "Devices with Removable Stoarge" as if a USB drive or device is connected. If you try to open the drive or click on them, you just get a spinning circle and ultimately an access error. I saw another post about something similar. I tired to open iTunes and got nothing, though I could see it in the processes for Task Manager. About 10 mins in, I pulled out the flash card reader, and as soon as the drives disappeared, iTunes opened.
My thought is that iTunes is trying to access these "ghost" drives on launch. Just like I get a spinning wheel when I click on these drives, I think iTunes is getting stuck trying to read them. Before I did this, I had the issue with several iTunes versions, I tried removing QuickTime, I uninstalled and reinstalled iTunes many times, deleted the iTunes folder, database, etc. Normally iTunes would eventually launch after 20 to 40mins, but once I tried to open any Preference or any System options, it would freeze for another 20mins. Backing up the device never completed. It was completely unusable.
I hope this helps someone else, because it was a painful road to this simple fix. Thanks to whoever stumbled upon a similar fix a couple pages ago. Its what made me try this.
Edit: This was done on 12.1, and I just upgraded to 12.3.1 and it still opened without issue. I initially downgraded from 12.3 because I thought it was the problem.