Do you ever get this sensation like you over-talked? Like you gave someone more information than was needed or was useful to the conversation? I don't know why this happens to me. If I think about it from a rational perspective, I didn't really talk that much, but I always get this feeling that I gave myself away more than necessary. Maybe it has something to do with my upbringing as I was taught to be silent and complacent, and my opinions were often ignored.
It could be that it actually depends on the feedback. For example, if someone replies to you with meaningful comments, then you feel it was worth it to express yourself. But you can never know what the feedback will be until you have spoken. So, really, you just have to risk it, and when you get poor answers, deal with it in the silence that comes afterward.