Ok first off, this is very normal. You are correct, it is most likely transference. I went through the same exact thing, except I'm a guy, and T was a woman. It started off as just a harmless attraction to her, then it developed into full-blown feelings for her. I never told her, and it is still eating away at me. I highly recommend you talk to your T about it. If he is a good T then he should know how to handle this. If you don't talk about these feelings they will get more intense and most likely get in the way of your therapy.