Carmen it may just be that you need more time and space away from him than you've given yourself. He wants back into the relationship he is familiar with and so he floated you a tester text as a hook and you took it. It happens. But it does not change the fact that aside from some words, nothing has changed. The only thing it takes for you to remain "broken up" is for you to accept it and act accordingly.
Even without addiction in the mix, I personally don't think it's ever worthwhile to immediately try to remain "friends" with someone you've just ended a relationship with. It's too messy and muddy and confusing. Dandylion posted a great thread within the last couple of weeks about time and space. They're often the last things we're willing to give ourselves when we are grieving a relationship, and they're the only things that make any difference.