Changed my url, can't access anymore how do I change back?

I wanted to change my url from https://romeosmarine.com/romeosblog to https://www.romeosmarine.com/romeosboatingblog I changed it in both the “WordPress address (URL)” and the “Site address (URL)” and then saved the changes and it gave me “Not Found, The requested URL /romeosboatingblog/wp-login.php was not found on this server., Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Apache mod_fcgid/2.3.6 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 Server at romeosmarine.com Port 80″. How do I fix this problem without having to reinstall wp. Thank you for your response.