Have you ever been treated for PTSD? That's another thought, I had, where derealization is concerned. Hang in there. Getting seen by a neurologist, can also help, make sure you don't have something going on with the physical part of your brain. Lesions on the brain or a Seizure disorder, types of things, may cause this, too.

Walking around, in a fog, dreamlike state, especially during a high anxiety moment. Something that sounds like it needs to be treated.