Upon installing Ubuntu 18.04, I noticed some applications were missing from the previous version as well as icons from the Adwaita icon theme. To attempt to fix these problems, I decided to begin by installing and reinstalling the Adwaita icon theme. This was done using the following command:
sudo apt remove adwaita-icon-theme
However, this started a chain reaction where every application on my machine started to delete itself until I had nothing left except a black terminal.
How can I fix this?