this is a major bummer, i'm sorry :( I have one possible hack, though it's not ideal: could you change your site name? then you'd have a new .neocities domain and you probably wouldn't get the redirect error. and if the redirect thing resolves itself, you should be able to change back to cephus later
I don't know how namecheap works but did you check all your custom dns/name server settings? It might still be connected somewhere on your account.
If the custom domain is still set in your Site Settings, Neocities will try to point to it. You should be able to clear the text box and press Update Domain to fix it.
I get a connection refused, meaning the DNS is pointing somewhere that doesn't exist. (which makes sense based on your last comments)
Try putting cepheus.neocities.org in your custom domain settings maybe? Long shot, but worth a try
I can't see it :(