It sounds like intermitted symptoms of depersonalization/derealisation secondary to your psychological state. Around 70% of the population with experience depersonalization/derealisation in their lifetime mostly secondary to psychological stressor and secondary to a organic state like a migraine. It is thought to be a shotdown to emotions when their is no escape and it becomes to overwhelming. It is likely a pre-wired brain response similar to the immobilizing "play dead" seen in animals that a brain reflex. To be a disorder it have to be constant for a period of several months to years. There most not secondary symptoms it will usually be a response to like anxiety or depression. If there is it have to be addressed as such and in many the symptoms will fade away when the primary cause is addressed. If there is no secondary symptoms and the symptoms stays despite they are addressed then depersonalization disorder is considered. It is thought that some are predisposed for some reason to not being able to normalize such a brain response and it gets to a constant maladaptive state.