You already got high GPA, why do you still need to 'prove' you are smart LOL? Anyway you don't need to prove anything to anyone. Nothing must be proven just bc others are thinking of you in random bad ways. Remember you don't need to take others srsly if they are uneducated about stuttering. I also notice you mention you feel bad when creating uncomforts in the conversations between you and the others. Why do you need to feel bad? You don't stutter on purpose, so no guilts in them at all. You are already trying your best to present yourself, so instead you should feel proud of yourself.