please help changed url

Well, I’ve been working on my blog and actually had the theme complete. I had been working under the url http://gator803.hostgator.com/~wapatu/ because that was what I was sent originally. Well, I went into settings and changed it to http://www.wapatu.com because that is what it supposed to be and now I can’t access anything. Please help….I can’t even get back in to change it back. Is there a way I can change it back in my hostgator control panel?