Never mind, I fixed it, but thank you so much for your help!
To log back into WordPress Admin page, I used CPanel and changed back WordPress and site URL back to its original through two lines of code:
Go to:
CPanel –> File Manager –> Public_html –> wp-config.php
and input
define(‘WP_SITEURL’, ‘[input original site name here]’);
define(‘WP_HOME’, ‘ [input original site name here’);
at the bottom.
That made my original site work (but look kooky). Now I was able to log back into my original site’s WordPress Admin and go to
Settings –> General
where I originally went to change my URLs. I went back into Cpanel and deleted the two lines of code (this lets me edit my URLs via WordPress Admin since they are locked if the code remains in the file). I refreshed my Admin page and changed both URLs back to the old. Went on my site and everything went back to original.
Not sure how/why this method works but it did. Posting this here in case anyone else runs into this problem.