But when I say I’m at odds with myself in moments when I do these things, what I mean is that there is actually a shrieking, hysterical, maniac voice in my head going

OMG, yes to this, all sorts of yes. I force myself out of my comfort zone nearly daily (sometimes forced out of it with no choice about it). I actually told a group of people that I was volunteering with once that I am an incredible introvert, that I'm panicking on the inside just talking to them, but that this is something I really really want to do this. It was a good ice breaker and getting that out there definitely helped.