In our case, H asked that the lines be separated when we separated, and I was in agreement with that. We are with AT&T. I had to be the one to make the request that his phone number be removed from the main account (I'm the primary account holder). An email was then sent to him, and he had to follow through with setting up a separate account with his same number. Since he stayed with the same number, same phone and just set up a new account, we weren't penalized or charged.
But if your cell provider has different rules, then so be it. As scary as it is to believe, January really isn't that far away! You stay strong and resist the urge. Or, like paige40 said, text her! That's what friends are for!