cannot access my WP anymore

Okay, I just did something really stupid, I hope I can be helped.
In ‘settings’ I carelessly set the url from https://www.myurl.com/wordpress back to https://www.myurl.com.
In both fields right under the title segment.
This was obviously quite stupid since now I can neither view my page nor access my WP backend anymore, as soon as I try to login I get an error404 message.
If it helps, the page is supposed to be https://www.steorrah.com/wordpress

does anyoone know what I could do?

thanks!