" I also felt like i’m instinctively changing my pitch of voice to higher when speaking the language aloud. Is that the reason?" If we perceive a trigger to stutter, then we anticipate or justify compulsion subconsciously convincing us to do compulsion. Our stutter habit tries to do 'unhelpful' actions to unblock. In your case, it seems that 'changing your pitch' as a coping mechanism turned into a helpful action but only in a limited situation (specific condition). In my opinion, it would be more effective to broaden this condition to: all situations.