Version 1: I tried to login and my account does not exist anymore. It says there is no account associated with the email address/username I put in.
Version 2: I logged into my account and there are no workspaces, everything is completely deleted. The workspaces I had are gone and all my work is gone.
You are logging into Cloud9 with a different account than you originally used. Because you can signup with your email address or integrations like Github, Bitbucket, etc. it is really easy to accidentally create a separate account.
Check email addresses you own for emails from Cloud9 so you can identify exactly which email address to use when signing in. You may have several different accounts on Cloud9 at this point so try several emails if you have them.