How do I create a feeling of safety in my body?

I’m new here and starting with the Stop Overeating workshop. The thing I’m struggling with is using food to make me feel safe, to calm me down. I have trauma that I’m working on healing (using EMDR with a LCSW). But my body and mind are always in fight or flight and everything feels like danger. Especially when I get triggered and have PTSD flashbacks ~ or my generalized anxiety spikes because something happens ~ I fall into food. And because the trauma is deeply buried (and not all remembered) it’s difficult for me to map the underlying thoughts and specifically to challenge them with the belief that I’m now safe.