Actually stuttering is a huge issue as it impacts a daily life activity, speaking. Any condition that make a daily life activity hard to perform will have huge impact on quality of life and feeling of agency. And that impact scales with the severity of the condition. That being said, having a mindset of "I will overcome this" or "This isn't all I am", Or "I can still do something with my life", "I can still improve and get better each day" is far better to have than a "nothing I try will work" or "what's the point of trying or doing anything since I have this condition" mindset. It's like that quote by Henry Ford, "Whether you think you can or you think you can't, you're right." You are far more than what you mind thinks you are. So don't define yourself and just live, doing your best each day, improving and always searching for better ways to use your time. Then the present will take care of the future.