I absolutely do not want this to sound flippant as that is not my intention at all…but he stated he felt it would help if you told him when you started to feel anxious. So maybe do just that. If need be, sit down with him during a non conversational moment and discuss it with him a little. See if he can help you come up with a phrase or sign you can give to let him know you’re getting anxious. And maybe even come up with a signal for when you’d like to change the subject to a lighter one without having to say “honey, can you shut up about that now? “