Need help changing site URL by updating 'A record'

Hello,

Brief description of my situation before delving into the problem:

1) Currently my blog/website is hosted on HostGator and served through a domain owned through HostGator (www.gregtassone.net/blog)
2) I want to keep it hosted on HostGator, but have it be served by a domain I own through GoDaddy (www.gregtassone.com).
3) I need to keep the email account associated with the GoDaddy domain up and running, so I found these instructions to simply update the ‘A record’ in GoDaddy’s DNS Manager, instead of changing nameservers. I believe describes my situation, so I followed those instructions a few days ago.

However, I think I need to do one or two more steps in order for this to work. Currently when I type in https://www.gregtassone.com it goes to the old website, not the new one I’ve built with WordPress.

Currently, my Site Address and WordPress URL in my admin panel both still say https://www.gregtassone.net/blog. When I changed those to https://www.gregtassone.com, all that seemed to do is turn my wordpress site into plain text and links when I visited the old address (.net/blog).

Does that take some time and should I just wait to see all the changes reflected in a few hours, or am I missing a step or two?

I also found this thread, which makes me think I am missing a few steps. I haven’t searched my database for all instances of the old URL to change them, and I haven’t changed the wp-config.php file because I’m not sure if my database name, database user ID and password will be the same (this is all described in posts #4 and 5 in that thread I linked).

I can access phpMyAdmin via HostGator to make these changes as well; that’s what I had to do to change it back to .net/blog so I could log into the admin panel once more.

I very much appreciate any guidance you can offer!