Can't Access Dashboard / Blog shows directory (I think)

Church website is : https://www.sewardumc.com/pages/blog/

Was redesigning existing blog. Wanted blog to show “www.sewardumc.com” in the address bar.

Here’s what I did:

The only changes I was making was in WordPress itself. I went to dashboard>>settings>>site address URL and changed “https://sewardumc.com/pages/blog” to “www.sewardumc.com” — thinking that would put “sewardumc.com” as the URL at the top of the page.

After that it looks as if it’s redirecting to a directory that doesn’t exist and I can’t access the dashboard anymore.

I’ve been to our hosting site and it looks like we don’t have have an .htaccess file as far as I can tell.

Previous answer to my question pointed me to https://www.sewardumc.com/pages/blog/wp-login.php but only points to “400 Bad Request” after I log in.

Thanks.