((((Dark)))) I'm sorry that you are having such a hard time.

I struggle with that too. One thing that has really helped me is journaling and looking for things that come up over and over and sharing that with T. I once gave my whole journal to T and she picked up on things that I hadn't noticed and it helped me feel less nervous about bringing up other things because I knew that she had already read about them and would know where I was coming from.

Another idea might be to try keeping a journal with your T. I'm not sure if this would apply to what you are having trouble talking about, but it might be a way to bridge the gap between sessions, keep your train of thought, etc.

Also, instead of asking her to challenge you, you can ask her what she thinks would be important to talk about with the understanding that if it is to triggering for you that it can be saved for another session.

Hope this helps!