I understand you frustration.
I am not expert, but my issues with OBS has mostly been with either bad drivers or Windows updates.
I assume you have made sure you have latest chipset drivers and gpu drivers?
Any issues if you look in Windows device manager?
I discovered some similar issues by using a utility in Windows. Start a command prompt as admin and type: sfc /scannow
It will detect and try to fix issues with your Windows installation.
I found several and ended up having to reinstall Windows.
Before you reinstall everything, perhaps take a look at Windows Update history and see what has happened since OBS failed to work. You might be able to restore to a point previous to last update, if there has been one recently.
Good luck
