[Solution]: Ubuntu 20.04 - Display became too big for the screen after installing an update for ubuntu

If you've updated your ubuntu kernel, ubuntu always stores the previous kernels. So you can try and boot into your old kernel by using "Advanced options" during boot and selecting the old kernel version. See if everything is working fine as before the update. If it does then you can try and delete the problematic kernels from the boot folder and updating the grub.

I have tried a lot of solutions but the only solution that seems to be working for ubuntu 20.04 is to navigate to the boot directory and deleting all the problematic kernel files

Follow the steps below:

cd /boot
sudo rm init.img-YOUR-KERNEL-VERSION-generic
sudo rm System.map-YOUR-KERNEL-VERSION-generic
sudo rm vmlinuz-YOUR-KERNEL-VERSION-generic

# then update both grub and grub2
sudo update-grub

sudo update-grub2

# Restart computer and hopefully your problem should be fixed now