Login page going back to login page with no error note

I’m so frustrated. My client is in the middle of a big launch. Her webhost is NetWork Solutions. Last night the automatic 4.1.1 update crashed their server apparently. They claimed it was all down for “scheduled maintenance.” It was back up in a few hours. I was asleep by then and didn’t try to get on the site. (I should have!) So this morning I cannot login. It just circles back to the login page. There are 4 sites, all have the same problem. None of them have the same theme or plugins in common. One of them is just used for redirecting links, so it is still running the default theme and has no plugins except Pretty Links Lite and another redirect plugin. They all are having the same problem. I have disabled plugins and the theme via ftp on the site that has the launch going on (which is going to create mountains of more problems that are fixable but annoying). I have made every single change I have found on these forums, including deleting .htaccess and a couple of different modifications to wp_config. Nothing changes. I suspect this problem is with the webhost…but I’m posting in here in case anyone else has this issue and knows the fix. (I have submitted a ticket with the webhost…we shall see how long that takes.) I see a few people have mentioned a problem with the login but none of them seem to be identical. **pulling my hair out here** Thanks for replies.