I wanted to tell my T, but I simply didn't trust her enough. It took me over a year before I could talk about it at all.

If you feel comfortable talking about s/i with your T, then go for it. Really, the sooner you can bring it up, the better. But, as my T has reassured me, they don't expect a client to share everything right away. It's okay if it takes longer to bring up some things.