Theme messed things up?

Hey
Just updated my whole website (gbfhobby.se) (themes, plugins, software) and shit just blew up.
I cant edit, when logging in it looks like I’m back in the 90s, my calendar widget wont work. Or yeah, now everything looks like a mess so I guess nothing works!
I deaktivated all the plugins and used the default theme and than switched to the theme I was using (twenty ten) but nope. Besides, twenty ten was one of the things I updated?
Does anybody know what I need to do?
Thanks
Alison