Screen goes mostly black, briefly flashes back on when power button tapped...????

[bismark22]

I turned my LG G4 non-rooted phone off today and then a few minutes later turned it back on. However, when it turned back on, after showing the LG logo then the Verizon logo, then the blank wallpaper, it went black except for the notification bar at the top and the triangle/circle/square at the bottom (the circle and square were faded while the triangle highlights when I press it but doesn't do anything). Also, the notification bar doesn't drag down when I try to pull it. The odd thing is that when I tap the power button the screen flashes on again but only for a tiny fraction of a second. I had to keep tapping the power button in this manner in order to make out the text on the screen when it flashed back on. The text is showing the Setup Wizard, which is asking me if I want to select English as my language. But like I said it flashes so quickly there's nothing I can do. I should also mention that I can access the camera by tapping the volume down button twice, can see a live view of the camera (no screen problems in camera mode), and can take a picture. I can even view the picture that was taken last by tapping on the thumbnail in the corner of the screen (the screen goes black again, but I can view the picture briefly by tapping the power button).

Does anybody know what might be causing this issue and how to workaround it? I tried booting in safe mode but it didn't fix the issue. Lastly, I will add that doing a factory reset is NOT an option for me. The data was not backed up on the phone, so what I really care about is accessing the data, not how to get the phone working again. Plugging the phone into my laptop via USB doesn't work because even though the device appears in file explorer it doesn't show any folders when I click on it.

So I guess my two questions are: how is this fixed? or how do I access the data? Thank you.