Alright, full stop here. This is wildly inappropriate behavior from a DM, period. "Do this thing you're uncomfortable with or get out." is unacceptable at any table. A player always has the right to say "I do not want to do this" and be listened to. If you aren't willing to compromise on something as simple as somebody not wanting to have to be as charismatic as the character theyre playing, its no wonder your players consider you an antagonistic DM. You are one!