Why is my screen flickering?

The image quality between log in screen and when I log into my computer changes, everything seems like it becomes over exposed.

Can use things like Netflix without issues, but when I try to read from a PDF the screen flickers like it is trying to adjust screen brightness, then starts developing dark horizontal lines across the screen, it is temporary,

It doesn’t occur in safe mode, have tried reinstalling newest update, did not help.

Can’t get apple servicing due to corona virus. help please!