wp-admin won't load (shows blank page)

I have two WordPress blogs hosted on a server I purchased at ixwebhosting.com. Though I was able to log in and edit these blogs without any problem 12 hours ago, I am now seeing either a blank page or a “Problem loading page” each time I try to visit wp-admin or wp-login.php.

I have tested my blogs on Firefox, Chrome, Safari, and IE, and I have issues in all browsers. I tried installing a fresh version of WordPress in a new folder, and I am still having the same issues.

I am sure I am using the correct URLs, as they are the same URLs that have been working for me for months.

You can view one of these blogs here: https://liliripe.com/clients/wordpress

Please help! Thank you.