Just an question, what did you do before it started doing this?
Also backup your videos which you recorded via shadowplay, depends where you set them to save, cause the DDU can erase it.
Have you tried DDU?
Download DDU https://www.guru3d.com/files-tags/download-ddu.html
Unzip it in folder on desktop, go to this site https://www.digitalcitizen.life/4-ways-boot-safe-mode-windows-10
and do the SHIFT+RESTART method.
In safe mode, run DDU as admin do the Clean+restart on Nvidia (Since you have nvidia GPU).
And now you have to try to install it with shadowplay.
If still doesnt work, I would suggest you OBS, a bit hassle in start, but very good in general.