Domain name change not working! Help!

[firefox200000082]

Hi. I just changed my domain name from an .x10.mx to a .com. Now my site isn't working at either of these locations! I'm trying to find the option to change the name servers (just in case it's not already set) but I have no clue where it is. This might not even be the problem! Do I just need to wait a bit?

Edit- I just changed it back to x10.mx and the index page isn't working! Gah!