Ah, that sucks. It's a deeply distressing thing, isn't it? That someone in a helping position would sexualize the relationship...

How long have you been seeing current T? Maybe you just need a little more time to develop that trust. Alternatively, you could always talk vaguely about the issue to test the waters--If "Id like to talk about some things but I'm worried you'll start thinking about me in a sexual way" is too threatening, how about, "I'm sometimes afraid that people in my life will think about me in a sexual way if I bring up certain topics, so I don't. What do you think I should do about that?"