If advice from a naive teenager counts, I've been dealing with the "shaky voice" and those in school on a daily basis just until now. I couldn't get why can't I just talk normally when there was someone unfamiliar to me around. I never questioned my abilities at talking with people, I'm sometimes relatively good at talking, I know how to do it in a way I'll make myself sound entertaining and interesting. But I just never seemed to succeed in it if there was some mystical stranger in the room, all it took was the other person being within a hearing distance.
But i started changing when I promised to my ESFJ mom (We really don't have that much in common.) to start interacting with her more if she'd stop telling me how to do things more efficiently. So what i did was basically just explain mbti to her to the extent she got it, and debate her in various issues using the mbti. You never seem to reach any kind of conclusion on matters debating an SF, so to me it was massive training on my retarded social skills. Just trying to figure out ways of explaining matters through the mbti gave me more confidence on interacting skills. My mom's SF way of explaining things seems illogical to my NT way, so it's a never-ending circle of me explaining the concept in my way, and then she does it in her way, and it goes on and on and on. What I needed was confidence on social stuff, I had the skills, but not the experience. So basically what I think you need is a frustrating and irrelevant debate with an SF. Mom's SF way of explaining to me seems weirdly "flawed" to some extent, so i dont feel "intellectually threatened" by her, you kind of keep really arrogantly thinking you're right all the time. Now I wouldn't mind a debate with an NT, but the hesitant, old me wouldve started crying, wet himself, cry again, then urinate again for no apparent reason just thinking of the idea of a heated NT debate. But the only problem is that the SF needs to be close to you, or the person just might never talk to you again, couple times my mom's come into my room after a debate almost crying, asking if im okay. She seems to take debates really seriously, and i end up telling her how she shouldn't take the stuff i say so personally, and after a while that convo turns into a debate too. I think you need experience on "feeling you're in control of the interaction", which basically kind of means winning debates.
Internet debates don't count as real life ones, I've never really debated matters in real life until now, so a simple thing like that made me feel alot more confident. First "real debate" i've had was with my mom, i feel manly. But if you're totally happy with your conversation skills, maybe its just an appearance issue? In that case going to the gym might be a better idea than making your mom cry about debating whether you should take your hat off inside or not.
Oh and i actually decided to make an account and post rather than just keep lurking? Weird.
so I'll go with - yes, take up going to the gym regularly. I did that when I was 18 and it changed my life forever.
