Changed URL, now cannot log in to wp-admin

So i took over a WP site project. Finished the content i needed to, then i did what i thought would be a simple change of the site URL from (stage.mysite.com) to (mysite.com)
Apparently i did not do enough research prior to doing this, as not only did it not achieve the intended result (pointing the finished site to the main url) but now I cannot log in to the admin dashboard for “stage.mysite.com” OR the admin dashboard for “mysite.com”

So just to be clear: I can no longer get into either dashboard.
I also realized that when i try to log in with either set of creds, the respective url will change from
“Stage.mysite.com/wp-admin” to “mysite.com/wp-admin” at the exact time i press the enter key upon trying to log in. This issue happens conversely too no matter which i try to log in to either stage or not.

Any insight would be greatly appreciated.
I have a temporary work around by DNS forwarding from the hosting cpanel.
Thank you for your time.