Changed WordPress Address Now Can’t Login
It’s kind of funny but, Here is an easy answer. I would add an EASY button here…
So you were messing around with your WordPress blog and changed the WordPress Address url and now you can’t login and the blog is all messed up. That setting in the WordPress general settings menu shouldn’t be changed if you don’t know what it means. It is to specify the location of the WordPress files on your domain. You can’t specify a different domain name either! You can use it to move the files to a different directory but there are additional steps needed to do it the right way. This WordPress guide will show you how to fix the problem.
via Changed WordPress Address And Cant Login.