I'm very sorry about what happened to you! :-(
This sounds like depersonalisation /derealisation. It happens to me, too.
What I find most helpful is reconnecting with my senses. Mainly exercise, walk in nature, yoga, touching things and feeling the material, texture, temperature... You can use your smell and touch.
When this doesn't work I simply accept dissociation is just a protective mechanism of my brain and it will go away eventually. I remind myself it's just a symptom of trauma and nothing bad will happen to me, I'm safe and capable of functioning even when I don't feel like it. Usually just thinking and accepting this makes me feel better.