That is the hard part! Does your T have experience in dealing with CSA? Hopefully she does and will realise her mistake when you address it. I would bring it right back to why you have this need to be uncertain about it. Ask her if she really thinks that this is you being 'manipulative.' Hopefully the focus will now be on the reasons for your behaviour and she can help to validate you, making it easier to ask your question.
If she still goes with the manipulative thing, I would tell her that this makes you feel misunderstood (if it does) and also afraid to bring up things that you would like to discuss. It really shouldn't go this far though if she is experienced enough in this area, in my opinion.
Let us know how it goes