Problem with blank theme set as default preventing WP Admin access

Hi,

I have 5 different themes in my Dashboard in the WP Admin Panel.
I accidentally made live a blank theme and then logged out of the Admin panel.
When I try to go back to the site and site/wp-admin urls, site is blank.
I can not log back into the WP Admin panel.

I use Bluhost as platform and downloaded WP into the hosting platform and not locally.

Any suggestions on how to troubleshoot this so can log back into my WP Admin panel and change to a theme that has content and functionalities like login?

your help would be appreciated.

thanks,
Dharmesh