Garry's mod text is gone

Garry mod worked fine today. Then i installed wiremod. When i got ingame i got a screen that said i installed it incorrectly. Then i installed it correctly and then i got a few things that didn’t show up at the game:
-All text was gone, except for the main menu.
-Some pictures were gone: Background of the mainmenu, icons of guns.

Screenshot of how it looks like ingame:

(Sorry for the big image)
So my question is: What’s wrong with my gmod and how can i fix it?

I deleted the wiremod maps and now gmod works fine again.