Congratulations for all the inner work you have done!! The phase of growth you are in now, will, in time, open new worlds to you. The longer answers are below.
I still don't know, as the whole premise of not being hidden is overwhelming. I spent years hiding, both physically and emotionally, in an effort to protect my self. Doing inner child work, they don't know the answer, either.
I found this step of recovery, from transitioning from inner child work ('intra-relational') to being in dialogue with a therapist most of the time ('inter-relational') a challenge, too.
[Lots of trust and reliability and reassurance that I won't be abandoned, maybe?
You are wise in this. It is a risk. Truthfully, every relationship, every person has limits to what they are comfortable with, can tolerate, in another. This is true for client and therapist. Each relationship is a process of 'dipping your toe in the pond', with one other, to see if you can comfortably tread through the relational waters, together.
Whenever you feel "unsafe", you can "talk about it", clarifying, stating your needs, letting your therapist know what helps you feel safe. How far do you want to sit from the therapist? Do you want your therapist to listen a lot, or ask you questions? If you seem tense, how to you want your therapist to help with kind words, relaxation or grounding exercises, What things do you NOT want your therapist to say? And if those steps don't work, Hopefully, over a 6 sessions, I would suggest that a different therapist would be a better option.
Just like me and you, therapists are people with their quirks, places of confidence and insecurity. Their internal job (infra personal) is to find ways to be anchored in their security, so that they can provide a sense of safety for you (interpersonal). Sometimes a client's issues are similar to their therapists, and in this case, there is empathy, but also challenges if the therapist can't be intra and interpersonally grounded.
This is the difference from childhood. You are empowered to see if the relationship suits you, or not. You get to have boundaries, and when you feel safe (which is a process, for sure, make sure to give it time), you can choose to open and share.
You are never without means is protection. You may want to discuss 'back pocket plan' with your therapist; when I feel uncomfortable, if talking about it doesn't help my safety, then I get up and walk around, or stand, in the therapists office. Another plan, could be that you can change the topic, or leave early. If I do feel a need for outside support to get clear about my needs, I've always found it helpful to have a personal friend, to talk to, about therapy; get another perspective.
I will share where I have misjudged the parameters in therapy, that resulted in 'negative' experiences, for myself. One therapist, repeatedly, did not understand how triggering it was to say a phrase. When I could change my response, I repeatedly asked my therapist to not use those words. When my therapist wouldn't stop using the phrase, i was at a loss and was being disturbed by his behavior. I resorted to a means that my former Gestalt therapist taught me; to yell.
Unfortunately many of today's therapists are not trained as Gestalt therapists, and, in their paradigm, see loud emotional expressions as extremely rude, and abusive, That was how my therapist experienced it; it was not my intention. Therapy was never the same. Eventually, I found another therapist, who was able to 'listen' and 'adapt' to my needs. (Summary, loudly emoting or criticizing therapists tells them you aren't happy, and they may, through subtle or blatant behavior, indicate you should leave.)
There was another aspect that I needed to be able to do, in order to share with my therapist. I needed to be able to physically relax in the presence with another. Doing a relaxation exercise by myself and with my therapist helped. Afterwards, I could modulate if I relaxed or not, depending on my needs or mood (e.g. It was nice to be able to relax enough to cry, and it was helpful to naturally find physical states where I wasn't frozen, but I would notice from my tension level that I was tense/feeling frightened or angry).
Relational resilience is what you are developing. You will always have your inner safety, in which to take refuge. As you listen to your mind and body, and verbalize your needs, and as your therapist can respect them, you will find comfort. Sometimes you may need to teach your therapist how to help you feel safe-carving safety out for yourself.. Navigating the waters, where you get to steer, will build your inter-personal confidence and strengthen your intra-personal confidence.
