Confidence in what? Wherever you're lacking confidence, improve in that area. If you're talking about your disfluency, then do some work there. (Easier said than done, for certain.) IDK you, so I have to just talk in the abstract, based on what many of us do. 1. Stop avoiding things. Speaking. Certain words. Events. Whatever. Avoidance because of your disfluency undermines your confidence. The sting of a bad disfluency lasts for a short period. The regret of inaction because you allowed your stutter to dictate your action (or inaction) hangs around much longer. 2. Work on positive mindset. Never criticize or blame yourself for stuttering. It's not something you chose. It's an impediment you have to manage to live with. It takes strength and effort to do so. i.e. You've done nothing wrong. It's not your fault. But you might find yourself being down on yourself about your stutter. When you find yourself in this thought process, stop it immediately. Do not allow yourself to berate yourself. You certainly wouldn't berate someone else for their stutter. Treat yourself better than you'd treat them. Changing harmful mindsets takes practice and effort. You have to work at this. But I promise you, if you persevere, you can reduce and eventually eliminate these harmful thoughts. 3. Seek out help with your fluency. You've likely had some sort of speech therapy before. And for whatever reason it didn't work. So what? Try again. Try with someone else. Not every program is well suited for each of us. Not every SLP or therapist is a good match for each of us. Sometimes it's just the wrong time in our lives. But most of us can improve our fluency. But only if we make an effort to do so.