404 error – Locked out of WP-admin

I was trying to resolve one issue and seemed to create a much worse one. I was trying to get my domain name to work with permalinks. All permalinks were reverting to the underlying URL rather than the domain name that was mapped to the wordpress subdirectory through 1&1.

The more pressing issue is that I now cannot access any admin functions, and the blog itself will not load properly. Going to my blog’s home page returns the following 404 error message:

Ooops…Where did you get such a link ?
Server cannot locate what you are looking for !
The Server tried all of its options before returning this page to you. 404You are looking for something that is not here now.

The content appears, but not in WP format. And when I try to log in to Site Admin, the URL is off by a character, which is what leads me to believe that when I was fiddling with the WordPress address (URL) and blog address (URL) fields on the General Settings page in Admin, I might have accidentally saved with a typo or something.

To be more concrete, my blog is at https://www.authorship2.com, but when I try to log into Admin from there, I get redirected to https://www.authorship.com/wp-login.php (without the 2), which gives me a File Not Found error. When I insert the 2 in the login URL, I am directed to an unformatted login page, and when I log in, I get the same File Not Found page.

Please help! I seem to be trapped in an endless misdirected loop. Where is that data stored so that I can access it and fix it? Is it somewhere in the database? I don’t want to mess up anything else with additional fiddling!

Many thanks!