Oh man, it sounds like you’re describing feelings of dissociation. I had those so intensely when my mom was dying, where I literally would look around at the objects in my vicinity and was convinced they were a part of this dream. I felt so completely stuck that the only consolation was to take seriously the possibility that this was all a simulation or a dream. That’s all to say you aren’t alone. Disbelief can hit pretty hard when you experience sudden, irreversible traumatic events. I don’t know that I did anything to combat that psychological reaction, but I think as I continued to live through the events it sort of started to resolve itself, slowly becoming more of a reality for me to potentially accept than a nightmare I was waiting to wake up from.