@Polyfractal - it may be a completely different internal experience for you, but that doesn't sound like a "safe space", but rather your internal experience which is a result of your trauma.
Safe spaces are something we create, free of the constraints of our illness, trauma, history, or rational constraints. They're a place that is limited only by our imagination, more along the lines of "If I could go somewhere, anywhere, that feels completely safe for me, it would be...".
Have you worked with that concept with your T? Personally, creating a safe space was something that came to me through a number of sessions or art therapy - because you're right, words sometimes completely fail and are too limiting. I used a combination of collage (magazine pics) and drawing.
It took quite a while, and I've had to create a few different ones - they're now part of my house. Safe places that I've internalised, and can go to when I want to feel safe.
I guess that's my way of saying: even though your trauma has left you feeling cold and lifeless and with a massive expanse of dark space internally, that doesn't mean that that's what your safe space might look like.
One of my parts has a giant Ficus in her room, because it brings her a sense of calm. Another part keeps cats, because she feels very lonely and isolated, but doesn't feel safe around people or constrictive relationships.
If you imagined a safe space for yourself, and it could be anything at all (looks, smells, sounds etc - like, it could be a forest that smells like the beach and has a whole heap of beanbags to sit on and a small fridge with an unlimited amount of orange juice and have a circle of small rounded colourful stones to hold onto - let your imagination go), and include anything at all that helps you feel centred in yourself and safe, would it be an underground industrial site (reminiscent of how your trauma feels)?
Or would it be entirely different, if it could be
anything at all?