Redirecting URL to a subdirectory – broken

I made a mistake trying to redirect my URL to a subdirectory. Now I can’t log in.
I was able to access the site with mydomain/wordpress but I did not want to see wordpress in the URL. I changed the domain by redirecting it to the wordpress subdirectory and then changed the Site URL in the wordpress settings (I probably shouldn’t have done both but now I can’t log in … it gives me the error : The requested page “/wp-login.php” could not be found. I’ve also updated the siteurl in the wp_options table. When I go to the site with URL mydomain/wordpress it displays the home page without the theme.

Can someone suggest how I can fix it?