Ok, so I just solved it.
I have NO clue how in the world this happened, and amazed at how precisely specific the issue was.
My Null registry was corrupt.
By going into (Windows Key+R) -> Regedit, I navigated to HKEY_LOCAL_MACHINE/SYSTEM/ControlSet001/Services/Null.
The Registry "Start" was set to a value of 4... but the value should be 1.
I'm starting to question how that happened. I do recall at one point having to modify the registry to fix my RAM from allocating too much virtual memory, but I don't remember navigating to this particular location in Regedit to do so.
However, all this sounds a bit familiar when I was discovering that sourcetree wasn't installing properly, and it turned into a discovery that git simply wasn't working because it claimed "dev/null could not be found".
This all seems to link up with what the Squirrel process (or whatever the itch app uses to pull from a git repo) was having issues with.
Sorry for the confusion, but at least it's all fixed now.
and most importantly, thanks for giving the effort in helping me with this strange problem. 👍