Well one thing you need to think about is that your stuttering is often separate from various other behaviors. So you need to know what you define “stuttering ruining your life.” If you avoid speaking situations and that’s what’s ruining your life, well that’s more of a discipline/anxiety issue. So you need to separate your stuttering into primary and secondary behaviors (reactions to the stuttering). And then on a side-note, you have to understand that there are indirect routes to improving your stuttering. Self-acceptance of stuttering can increase stuttering, but also improve fluency. So you need to be in touch with the indirect route and direct route to what you are trying to do. And to the question how much can your stuttering decrease. Well, I think there is no direct answer to that. It’s really as much as you can figure out about recovery for yourself. That’s the answer. It’s like asking someone from poverty what their max potential income could be. Well, we don’t really know; as much as they will do is the answer.