Upside down mouse cursor and inverted position on Ubuntu 18.04

I tried following these instructions, but that didn't work. Then what I did was simply open Terminal using Ctrl+Alt+T and invert the screen using

xrandr --output eDP-1 --rotated inverted

Then running

sudo apt-get update
sudo apt-get upgrade

After rebooting, everything went back to normal.

To prevent GNOME from communicating with the sensor hardware I ran the command

sudo apt-get remove iio-sensor-proxy

This solved everything for me.

You can just run

sudo apt remove iio-sensor-proxy

and reboot then. Everything would come back to normal.