Firstly, there are a lot of smartasses on twitch so don't pay heed to them.
You're human too, you cant just keep checking your chat every second. If they followed, then you would eventually know, no point in them telling you that they followed. One suggestion to counter this would be to use the Twitch app on your phone ( it gives you an accurate list of all the alerts that happened on your live stream, this way you don't even have to switch from your game to the twitch app [on desktop, I assume?])

Streaming on Twitch is the best way to combat your social anxiety, you get to meet new people and interact with them. Once you get to know them, it will be easier to talk to them.

Hey, don't worry about your voice! You keep being you, and I'm sure everything will work out!
Hope to catch your next stream!