Can't access admin page after WP install

From what I can tell you are sitting on WordPress servers, and not actually “self-hosting.” If you were self-hosting with GoDaddy then you would be pointing the domain to their servers, and would have moved the content. But, what I am seeing is that you just point the DNS for the domain name to WordPress DNS. With all that said, this doesn’t look to be that big of an issue.
https://kusadama.wordpress.com/ redirects to https://kusadama.com/ and https://kusadama.com/wp-admin redirects to https://kusadama.wordpress.com/wp-admin .

Try updating some content and see if it updates on https://kusadama.com/ . I would bet it does.
THANKS!

I just changed some content and it is indeed updating on https://www.kusadama.com.

The fix should be to use GoDaddy’s nameservers then?

If you are wanting to self host then yes. Not sure your reasoning for going self hosted, but you need to make sure that your entire site is moved over to GoDaddy prior.

https://codex.www.ads-software.com/Moving_WordPress

If your site isn’t really having any big changes to it(i.e. Themes, Plugins, etc), then I would suggest staying on the WP servers and saving a buck or two.