Thanks everyone for you input and your ideas. It really helps me to come to a better understanding of what I need in situations like this.

Ultimately I'm quite confident that T and I will be able to talk this through and to find some solution that works. We always have in the past so far. I guess by seeking your input I just want to be more 'prepared' for next session, to develop a better idea of what I need/expect of my T in those situations, so I don't get sidetracked.

@rainyday: Printing this post out sounds like a great idea, the problem is, that I don't live in an English-speaking country and I'm not sure about T's English skillz. I'm probably too lazy to translate this all. But just having this conversation with all of you help to see things more clearly.

@unaluna: Downhill for me means I freeze, like completely. I just go numb and in situations like this it takes all my strength to concentrate to keep breathing. At some point I might start moving again. Talking? Takes much longer.
We're working on grounding, on staying present, on not checking out so much, and it has become much better, I usually notice the first signs by now so I can actively push against zoning out, but still...

@skeksi: Yeah, ultimately I know that it should help to talk about all this. And that it should get easier with time. And as I said, my T really doesn't come across as authoritarian or judgmental. These are all my little homevidoes in my head, projecting/transfering onto her what I've experienced in the past. So even speaking up or asking for what I need in itself seems to be immensely triggering at the moment..

@TishaBuv - I feel for you. Having a T that attacks you just isn't helpful at all. And having your partner emotionally abandon you in a situation like this... So sorry you went through that.
The traumatic experiences from the past that pop up in present situations like this... On one hand it does help me to get a better idea of what I must have felt like when I was younger (as zoning out is not a recent feature of mine) and it does give me a tremendous amount of material to work on... On the other hand, it does get a bit much at times. I just wish for a pause button in situations like this, so I'm not constantly caught up in this. or for someone to grant me a week's holiday from myself so I can regroup a bit a get some more energy for the steps ahead...