Ruined my website! HELP!

Okay, I couldn’t understand why the only way to get to my website was through http://www.influenceaction.org/influenceaction and if you just typed in my regular domain (www.influenceaction.org) it said the site was under construction and wouldn’t show anything. So I tried to change it. I went to General Settings, and changed the WordPress URL to http://www.influenceaction.org and the other one underneath it as well to the same thing.. and now I can’t login to my dashboard, I can’t see my website, nothing. It’s all gone or screwed up! Please help!