my first blog – change domain-name

hello, i am a new member here. i have the following question:
a week ago i’ve published my first blog under the domain-name: http://www.hotusasoundz.com. The topic is about jamaican food. after that, i wanted to change the domain-name into something that fits to my blog. so i purchased another domainname called “www.realjamaicancooking.com”. What i did now: i logged in on my wordpress-dashboard and then “general settings” then i changed “WordPress Adress (URL)” and “Site Adress URL” into “http://www.realjamaicancooking.com”. Now the site doesn’t work anymore… when i want to go back to the wordpress-dashboard to change it back to old, it cannot find it anymore…do you have any idea why this doesn’t work ?

i simply wanted to change the domainname of my blog from “www.hotusasoundz.com” to “www.realjamaicancooking.com”.

Can someone help me please.. i really dont know what to do now…

thank

Mike