I think in your case, if you think it’s appropriate, would be to just stop speaking for a bit. Give yourself a chance to reset and dump whatever care you had about the last question/conversation and chip in again when you feel ready. It’s perfectly fine to say I don’t know the answer (even if you know it) or just literally wave the question away a bit. But do make sure to try get back into the conversation eventually (ideally before the class ends).