What you are experiencing is called depersonalization, defined as "a state in which one's thoughts and feelings seem unreal or not to belong to oneself, or in which one loses all sense of identity."
You could also be experiencing what is known as derealization, which is defined as "a feeling that one's surroundings are not real, especially as a symptom of mental disturbance."
Both of these are quite common manifestations for those of us who have anxiety/panic. They can be extremely frightening when we don't know what they are or what is causing them.
The Mayo Clinic has written........"The exact cause of depersonalization-derealization disorder isn't well-understood. However, it appears to be linked to an imbalance of certain brain chemicals called neurotransmitters, which can make a brain vulnerable so that heightened states of stress and fear may lead to the disorder."
I would urge you to see your doctor for a complete physical to a frank discussion of your anxiety and these experiences. Therapy will definitely help you deal with or overcome these issues and meds may play a role during treatment, but that is for you and your therapist to decide.
You are not going crazy and you sure aren't alone!
I wish you the very best and a quick recovery
try checking your thyroid
Good idea........which is why I recommended he have a COMPLETE physical as his thyroid function would be checked.