Do you mean CBS All Access? You did not actually specify it by it's full name. If it is (and I think it is by your own description), you are limited by just 2 simultaneous concurrent streams per account. First check if someone else is using it too on your account with your permission. If not, check to see someone else has your email and password and is using it without your permission.
If you can or cannot determine if your account is being access by someone other than yourself, the best thing to do is quickly change your password. I would consider using another email address as well, but the most crucial sensitive part of your log in info is your password. Make the new one not guessable, not so easy to decipher, and very drawn out and difficult to type. Please no 123456, ABCXYZ, PASSWORD sort of thing.
I change my passwords, PIN passcodes, and the like periodically as to make sure if these sensitive information falls into the wrong hands, it won't work anyway. Try it. If this does not work, then contact CBS All Access directly. The phone number and other contact information is on their website.
