Everything I’m going to suggest is based completely on just a couple of quick observations done in a browser, so treat it accordingly if I’m off the mark.
It looks like the WordPress content on your site is being pulled in through the iframe from this domain https://douglasvw-see-our-happy-customers.com.
The WordPress site on that domain is no longer rendering your theme (at the least) properly – html appears to be okay, I can see your readme file with no problem, and this renders blank as expected: https://douglasvw-see-our-happy-customers.com/wp-content/themes/index.php, so php probably still works, however, I don’t quite understand the base64 encoded portions of the the WordPress files being displayed when I try any other index.php or the xmlrpc file. A source code obfuscation device or plugin? ..I don’t know, I didn’t bother to decode it all… anyhow.. I would have expected something a little different when accessing those files directly.
First, try using your ftp client to rename the active theme on your WordPress site ( or completely replace it as already suggested, if you are already using the default theme), and then try logging in again at /wp-admin to let the default theme take over, and see if that makes any difference. You can do the same to troubleshoot any plugins you might be using by temporarily renaming the /plugins directory to see if that helps.
The domain where your WordPress site sits appears to be hosted by GoDaddy. Maybe contact the support staff where you have that domain hosted and see if they can shed any light on the issue before going much further.
Some reference material: Login Trouble
FTP Clients
