Can't access dashboard

I recently changed my password as requested by WordPress. However, when I saved my next post it’s like it saved in a brand new blog – still with the same name, and only that post. I can still see my “real” blog, and all the posts I created. But when I try to log in, I get the following message:

You are logged in as “paulvetterblog” and do not have the necessary privileges to access the dashboard for “Paulvetter’s Blog”. If you are not “paulvetterblog”, please log out, and log back in with your username. If you are “paulvetterblog” and you need access, please ask an administrator of the site to invite you.

Please help!