My wp-admin has been disabled

I am designing a new charity website at digitallystrong.co.uk/arclib. It is a membership site so I have installed Buddypress. After assigning pages to the Activate & Register buttons in the dashboard I then logged out. Now, whenever I try to og back in and visit digitallystrong.co.uk/arclib/wp-admin OR digitallystrong.co.uk/arclib/wp-login it just takes me to a Registration page. I can no longer access my Admin login page. I’m completely stuck. Can anyone help me please?