It says my email address has already been used.

The Social Rotation system will only allow one email address used per account.  If you wish to add another account with the same email, we suggest adding a + to your original email.  

For example:

your current email that is used is Name@gmail.com 

You could use name+sr@gmail.com.

That would provide you with a new email address that will still forward to your original email, but also allow you to use it as a new address.