No, you don't stutter because you _think_ it. You stutter because you _have_ a stutter. It's not that you're failing to _not_ think about stuttering. It's just that you stutter because that's what stutterers do. So, you see, none of this is your fault or your doing!... Stutter varies a lot. It's something we need to get used to. Have you tried speech therapy? Maybe there's something that'll work for you in terms of ongoing management.