Issue When Switching to a New Domain URL

Hello,

I was formerly running a site on A.com (for example). Recently, I decided to change my site’s URL. Everything else was the same (still same hosting provider – Laughing Squid – and still using WordPress). I changed the nameservers to point to Laughing Squid for the new domain (let’s call it “B.com”) and also updated my URL in WordPress’ settings.

However, both websites (A.com and B.com) now only show up with “Oops! Google Chrome could not find that website!” as if they don’t exist). I would have assumed B.com would have been working. I can’t even log in to my wordpress dashboard with either of the domain names. How do I fix this?! Please help!