Changed URL and Cannot access now

I need some guidance with trying to gain access to Dashboard to make changes. I changed the URL from the website and now I cannot login. I have no experience with phpmyadmin and I am working on a MAC. Any help would be so appreciated. Thanks. [hr]
Oh did I mention Im desperate!!!

we don’t have psychic powers so you might want to explain dashboard to what

It was a long night! Here is the run down, I was in Wordpress and I changed the URL and now I am not able to log into WP to make changes. I need to know if there is a way to access WP again to make the changes without using phpMyadmin. I can access the website but the pages are distorted and I cannot access the WP to get access to Dashboard to make the changes. I am waiting for the info on the FTP server from the person who initially set up the site. Any help would be greatly appreciated.

It will also help to know where you changed the URL. Did you do it under Settings>General
For FTP access you can do that yourself by going to Users>Manage Users and just change the password. The username you will see at the top. That is if you have panel access