Galaxy S3 pull down menu, home button, app switcher button and user switching not working
I have a Galaxy S3 (GT-I9300) running Lineage OS 14.1. After running out of battery last night and restarting it this morning the pull down menu, home button and app switcher button stopped working. Also widgets on my homescreen don't load and the notification light is flashing red constantly, despite none of my apps using red for notifications. Notifications dont show up on the lockscreen and in the pull down menu either.
The pull down menu can be opened, but my layout has changed and I can not expand it, as I usually would, to see the other toggles. When I tap on mobile data, which usually expands the menu, it shows the top bit of what it usually shows, but cuts the rest off.
After some digging around on the internet it was suggested to boot into safe mode and switch the user, however I am not able to switch users (the user menu in the settings won't open). I am also not able to access the developer options (it says "Developer options are not available for this user").
So naturally I wanted to perform a factory reset. However I can't back up my data to my PC since the notification to enable USB file transfer doesn't pop up and the google drive backup won't start either when tapping synch now.
If there is any more information you need to help me figure this out, just let me know.
Thanks in advance,