maybe you could approach this from another direction. maybe you could try talking to your t about what she does that makes it more difficult for you to open up to her. i'm not in any way suggesting it's her fault you can't open up--i'm just saying this might be another way of working up to telling her more about what's in your head.

when you first opened up to her and told her how suicidal you were she wanted you to tell your parents. obviously, this didn't exactly motivate you to open up further. so how would you have preferred her to handle that situation? maybe that's a place you could start.