Black Blobs Appearing on Phone Screen, Can't Access Anything

Hi there, I’m kinda pulling my hair out trying to figure out this mess I’ve gotten myself into with my Samsung A40. My phone hit the ground hard by accident and despite no visible cracks, black/purple blobs have started spreading throughout the screen. Worst of all, touch screen functionality has ceased and I’m stuck in the Lock Screen. Rebooting it doesn’t work, which isn’t aided by the fact that the volume buttons don’t work to reboot it in the first place, so I had to run it out of charge to restart it. Alas, the touch screen still won’t function and the blobs are spreading.

I understand there may be damage to the AMOLED display, but I’m no expert on this. I have a lot of files stored internally that I never got around to backing up elsewhere and I’m very scared of losing them. Is there anything I can do to get into the phone and grab my stuff before the whole screen becomes unusable? Should I turn it off until I know what I’m doing? Is there any course of action I should take to help mitigate this problem? Thank you so much for your time.