If I had to make a guess, I'd say you probably can't talk in therapy because you are very afraid and a lot of defenses come up- defenses that have been very necessary for keeping you safe in your life. It's hard to learn how to be in a healthy relationship and to be open when it used to be the LAST thing you should do, if you wanted to be safe. So panic and terror and chaos come into the picture, because you're disrupting patterns that were necessary for your very survival before, but in therapy are not.

Does this make sense to you??