Touch input rapid ghosting, but sometimes works.

So this phone has been fine and then very suddenly wasn't. I woke up this morning and unlocked with the back fingerprint sensor to turn off the alarm and the phone wasn't responding. I have the setting turned on to see touches I guess and I can see rapidly reporting touches all along the edges of the screen. It pulled up lots of apps, was hitting the home button back constantly, and nearly sent a text. All extremely quickly.
I held down the buttons to restart the phone and it does the same thing on the password input before it fully boots.
I wiped the phone very thoroughly and managed to get back into the phone once, but it messed up again.

misc info
No contact with moisture. the phone has had some flex for a while as if it gets stored in a back pocket, but that has never been the case. It is very minor and may have been present from a previous owner after refurbishment.
I need back into this phone at least once as I'd like some of the newer photos and recordings that haven't been backed up.
I've ordered a new phone, so time isn't a huge issue. I'm wondering if it's possible to disconnect the touch sensor and just use another input through USB C, but that will need to work before booting into the OS to be helpful.
Any ideas are appreciated.