Academically-gifted but bad at vocal communication. Am I in trouble?

I think there a lot of ways to learn how to overcome your problem. Perhaps you should see a speech therapist and see what they recommend.. it might simply be related to anxiety or maybe you have to strengthen something through repetition. I do think it would put you at a disadvantage in most cases.. in my experience, if you're able to speak well.. as when conducting an interview properly for example, it's generally just as or more important than grades. but I think it's definitely treatable.. so definitely look into speech therapy. Sometimes it could be really simple.. something like stress could cause that.. that sucks that you have that reputation now, must not feel too good.. but try not to let it upset you too much.. be confident.