6 years?! That's a long time man...I feel my stuttering was also the worse in university when all I did was study and go to class. After not talking to people most days my stutter was also insanely bad. However with neuroplasticity it's about training your brain to talk again, I felt my stutter improved greatly after I started working and was forced to talk to people all day long. In grade school/high school it was the same where my stutter was not that bad because I was talking to people all day. I think you too could see improvement in the right environment.