From what I've experienced, things like this are really just learned behaviors to escape the stutter. You at one point rolled your eyes back and got through a stutter at the same time, so you associated the secondary behavior with stuttering. I have facial tension on my blocks, and it's the same thing. The only way out of it is to start disallowing yourself to do the secondary behavior when you stutter. It takes quite a bit of concentration, as the secondary behavior has likely become involuntary and paired with the stutter at this point. And trying to stop the secondary behavior will probably make you stutter worse and really want to do the it to escape the stutter, but if you can get used to not doing it, eventually it will stop happening automatically when you stutter.