Good morning Tokidoki,
I am sorry you were flooded with memories. This happened to me when I began therapy as well, and together, T and I have slowed things down quite a bit. I do believe we have to go through the difficult memories, but only in the amounts we can handle without being retraumatized.
If you can share with T about how you felt after session, and before session, then the two of you can get together on how best to proceed. You don't have to be re-traumatized week after week. In the beginning, I believe it's most important to work on solidifying your relationship with T before you proceed to the difficult stuff.
It is so hard, but I believe you are traveling in the right direction.
Best of luck and take gentle, gentle care right now.