Login as administator to website

Hi, I can login to my website using the masking url to do the admin work. I cannot then try to access my website as the administrator to lodge my daily comments. It did work up until 6 days ago. If I access the site either for the wp-admin pages or via the web browser I can only enter as a guest.

Is there a log somewhere to check what I changed

Regards
john

The page I need help with: [log in to see the link]