We are more vulnerable and more sensitive in these relationships than we normally are. Whatever it was that he said that lead to you falling apart must have some significance. Reactions like that in therapy are very important. If you can talk about it and figure out what it was, that could turn into a huge step forward. Nothing wrong with you though, that's part of what therapy does. Sometimes it hurts though, doesn't it? But it will feel better if you process it and understand it.