Accidentally changed the url

Re: the comments above: Read http://codex.wordpress.org/Changing_The_Site_URL

It says:

There are four easy methods to change the Site URL manually. Any of
these methods will work and perform much the same function.

And the Codex outlines each one. The first one is the easiest; add these lines to wp-config.php with FTP or your hosting control panel file manager:

define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');