WP-Admin page does not show up

I cannot log into my membership site. When I use /wp-admin or wp/login, it redirects me to the login page for my clients. So since I cannot sign into the site, I can’t change/edit/post anything on my site. I tried deactivating all the plugins/ deactivating the theme, but it didn’t work. The site is fully functional and people can get into it, but i can’t login to change it. What do I do? I tried all the stuff in the wordpress Codex and have not had any luck.

thanks