One thing to bear in mind as the day approaches is that the T will not just sit you down, get out a pen and note pad and begin firing embarrassing personal questions at you. A therapist is a pro and knows that unless there is trust nothing can be achieved, so some sessions will be about trust-building. My T in Germany never did get us around to the CSA itself; looking back I can see she knew I was too freaked out, too depressed, too ashamed, too horrified, whatever. And the T with whom I made the most progress waited about two months before asking me if in our next session we could begin to talk about the CSA itself - "what happened". And by then I was ready, so it was okay.
I hope others will join in here, but I can tell you that when I started therapy all the world felt like some kind of mad Jumanji-style wilderness. It seemed so unsafe and I was on red alert ALL the time; I would get home and feel like I wanted to collapse into tears, I was so wired. And yes, at first I dreaded going to my T appointment. But after a time I noticed that I felt safe again when I stepped into the Psychology Department. Then later on I noticed that when something happened I would think Oh, okay, I need to write that down so I can check with Gillian next time. When therapy ended I really felt like I was losing a precious resource.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)