Help! I changed my homepage to a "site offline" page, but now I don't know how to access my account

I changed my website to be in offline mode so now it shows a "site off-line" page. The problem is that now I don't know how to access my admin account. I thought I remember them showing a new url to log in to access the account, but I forgot to take note of it and write it down. Does anyone know if it is a standard url that is a variation of the domain name page and if it is similar for everyone. Is there a way to log in off the Drupal.org website. What do I do if I can't log in again? Do I have to unistall Drupal through my hosting account and reinstall it, or what? Please help!

Thanks