Thanks for the replies! I agree with you, especially about building self-discipline and growing as a person by overcoming an “impossible” obstacle. I don’t consider myself frustrated anymore, I think I’ve managed to move on from that negative headspace.
I discovered another useful thing about stuttering (or any other disabilities): the people who really matter in your life won’t look down on you and feel superior just because you stutter. It’s a great test whether the other person has a kind spirit and if not, maybe that person has no place in my life.