You sound young. We are the hardest on ourselves when we stutter, which only makes stuttering worse. Even if others are harsh to us because of stuttering, we are prone to internalizing others’ reactions to us and reacting negatively. I have been practicing not giving a fuck and it helps a lot. It’s nowhere near perfect, and much of the effect is on my mental health, but hey, I talk more, have better relationships, and I am happier.