I experience this but it is only momentary. I can think my way out of it. I start by identifying the simplest things around me that I know are real. This is the start of creating a context of myself and environment. Touching something or moving is usually enough.

I also have to orient my memory. By this I mean I accept that my memory is unreliable. Again, I start by establishing a simple context. Do I know what day it is ? Do I know where I am ? Once I get a few of these contexts established, the rest falls into place quickly.

It is important that I do not get stressed out by this sense of ??????? Anxiety only makes it more of a problem.

The big problem in my view is that we normally live with an automatic context of who, what and where so we get lazy with our attention. As brain injured, we need to purpose our thoughts more. This is no different that the Stop to Think exercise. If we just stop to think, we can usually reconnect to our reality.

I struggle with this most when I wake up from a very real dream. I need to put serious contextual effort into determining where the dream ended and real life starts.

Learning to live life on purpose rather than on autopilot takes a bit of effort but it becomes a habit.

Hope this helps.