I know there must have been preverbal trauma in my life, probably as a newborn preemie.

My T would probably do EMDR or SE (somatic experiencing) with you. You don't need words for that; you say how it feels in your body. Then you can learn to experience it in a better, nontraumatic, corrective way, by doing some kind of comforting action, maybe hugging yourself, or patting your arms slowly. Maybe ask your T if she thinks somatic experiencing would help you, but you'd have to find another T who does it.

My T is doing work about being safe and loved in my mother's womb. Even if you weren't, you can visualize it, she told me. It's a way of working with your body, where you feel the preverbal stuff.

Or maybe you can color your preverbal feelings?