help! Put the wrong address into the wordpress url box

Okay, this is an emergency!

I’m in a catch-22 situation.

I accidentally typed in the wrong webaddress into the settings/admin page of my wordpress blog.

In the box which says: wordpress url I typed in http://www.bettyburlesque.co.uk instead of http://www.bettyburlesque.com

Now the entire site doesn’t work because it’s trying to find files from the .co.uk site which doesn’t exist!

So I can’t even login to change the setting..

It’s a bit of a stuck situation, would greatly appreciate all advice and assistance!