Hello 1stepatatime
It's hard for me to know what is happening as I don't know you or your therapist but it does feel that it needs to be discussed. There will be both of you in there - you and how you feel and relate to others (your transference to her) but also she will be in there too. It could be that something she does sparks a reaction in you that unconsciously (or consciously) reminds you of someone in your past but also it could be that your therapist is defended in that she can't go near something because she hasn't worked it for herself either - and that might be some of what you are feeling.
I would like to hope that she has enough about her to be able to work this out with you. I felt so sad when I read your post - sad that there wasn't an opportunity to discuss how you feel in relationship with her. And I am afraid I can't guarantee she can do it - that she has the knowledge or experience to help you work through it by being open with how you feel and her not retaliating, rejecting or defending. The only way to know is to have the courage to talk about how you feel.
There could be a number of reasons she was quiet - it could be because she was waiting for you to continue - giving you space - and often we can interpret it as an absense if we are used to absense. Or it could be she is struggling to go near the erotic bits/ doesn't really understand transference/projection and disappears behind a wall to protect herself from what she can't deal with, or it could be lots of things inbetween!! The only way to understand is to talk with her about it.
Unfortunately many therapists don't get it and will abandon their clients either physically or often in an emotional way when powerful transference begins. They will shut down the part of themselves that can't cope therefore abandoning that part of the client. I'm not sure if it is boundaries you are experiencing or whether it is defenses? - and it won't just be about you or just about her. It is her job to sort out herself and not your job to protect her. You are doing what you need to do - and it is very important that you are able to work with how it feels with her. If she can't do that then you have to find a therapist who can work transferentially, especially with the erotic maternal transference or you are likely going to get hurt.
If you were my client I would have very much heard that you were trying to tell me something and most certainly would have explored it with you - often directly, but gently, speaking how it may feel so you knew I understood something and that it was ok to talk to me about it. Perhaps she missed it that time and needs to be reminded?
You are very intuitive and there is no doubt you are feeling something and it feels the 'wall' needs to be spoken about to understand what it might be.
I hope you can talk to her - it feels your post could be a starting point?
Moon