You have my sympathy.
I'm very confused by what's happening with Google and everything they own.
My university changed their email account to Google to save money I guess. Now I can't log into Youtube because the university account doesn't allow Youtube membership. It won't let me log in the way I used to and I can't log in with my real Google account because it automatically switches over to the university account.
I've tried reinstalling Firefox and using Chrome and Explorer, but it always recognizes me. This makes me think its more than a cookie issue.
If I actually made videos myself and had subscribers, I don't know what I would do.