I know this goes against what is said here but having severe blocks and repetitions during these type of situations is not socially acceptable. I have felt far worse about my about myself failing over and over again in these situations than just not trying at all. With everything life throws at you (work, stress, talking fatigue, etc) taking an additional unnecessary negative hit to how you feel is not worth it in my opinion. I still talk of course, but the conversations I have are not dependent on timing.