I used 'apt-get install -f'. Now all my applications are gone and those I have reinstalled look wrong.

I used 'apt-get install -f' when prompted by the updater. Normally this should have fixed the problem, however in my case it seems to have damaged the system quite a lot. Now all my applications are deleted permanently and those that I have reinstalled have odd GUIs. For example the software centre looks like the image below.

This extends to the login screen and a multitude of other applications.

Is it possible that this happened because of an interrupted internet connection when updating, or something else? Is there a quick fix, or do I have to manually reinstall every application?