Talulah, that is so intense.

I would feel rejected big time if that happened to me. It sounded like on the one hand she wanted to encourage you to explore your past, ostensibly in the service of greater present healing. Then when you were ready, she shut the door. Some T's are not comfortable with delving into the past. They are "here and now" sorts of helpers (and that can be exactly what some people want). My first counselor was like that--very CBT, never getting at the root of my problems, so they never got solved. She was focused on trying to lessen the symptoms but we got no further. If you want to deal with your past, please tell your T.
It should be you who decides what you want and need to work on, not her. Maybe she simply feels it is outside her scope and expertise and could provide a referral to someone with the skills and orientation you may be looking for.
A lot of your post could have been writtten by me. My new T is ready to go anywhere with me. Dealing with past trauma has so helped me with present life and dilemmas. It's a hard journey but worth it (to me)!
Good luck,
sunny