Emotional numbness is a coping mechanism for not confronting one’s emotions and trying to shut down and neglect the feelings that make one overwhelmed. Though it is normal when short-lived, it becomes a pretty unhealthy thing to do in the long run. Restricting oneself from feeling and confronting the emotions one feels at the moment can add up to not functioning correctly and hinder one's ability to feel genuine. 

https://yourmentalhealthpal.com/what-is-emotional-numbness/