Changed Site URL and Lost Access

I had changed my Site URL in www.ads-software.com and lost access to my account, editing pages, everything and have no idea how to go back or get into it any longer. (from https://www.Merridethhawkstudio.com to https://www.merridethhawk.com)

I am a complete beginner, on an older forum it discussed FTP and/or wp-config.php, but I have NO clue what any of that means or how to do it.

Any detailed directions or help would be GREATLY appreciated!

The page I need help with: [log in to see the link]