Maybe you and your t can talk about your concern with talking about secrets. Let her understand you are not trying to get out of it, just that the subject creates a lot of reactions from your system. Maybe you and your t can talk about how the conversation will go and that it is ok for you to let your t know if you are getting too upset. This way there will be some rules you can both agree on during session while talking about secrets. Write what you want from sessions about secrets and see if your t can work with you.