Update just killed all my settings, and I can't get them to work.

I just downloaded the latest update, and eM Client acted as if it was a new installation. All my settings and e-mails were gone. I was able to retrieve e-mails for one address, using gmail, which I channel all my e-mails through, but for the other one, I can’t get the settings to work. And some of the e-mails are coming in saying the message will be downloaded the next time I go online, only I AM online. HELP! This update is a disaster. 

sounds like you accidentally skipped the data migration from eM Client 6. This is needed because eM Client has a new database structure.
You can import these data manually using the Menu>File>Import>Import from eM Client 6 option.