I know exactly how you feel. I’m 98% fluent and I’m considered as a non-stutterer…until I have a small random breakthrough. Even we who are very fluent know we are still stutterers. I can never lose that stigma. I only became this fluent at the age of 67. I’m 77 now and those years of embarrassment still haunt me. Nobody else knows when we have to word substitute but ourselves. There is always that fear in me that my ‘secret’ will be revealed. I need to just accept the fact that I’m a mostly fluent person who has a stutter.