After I separated from my "x," I had multiple experiences of what you are describing - some with obvious reasons and some were simply reactions that seemed to come out of nowhere.  The more I built up my self-esteem and the more healing I did, the less I had panic attacks.  Fast forward about 36 years, I can still have moments when my entire body tenses up but my self-talk helps me relax as does talking things over when its really hard to relax with my sponsor or a fellowship member.  Trauma does a number on us and I don't think we ever get to a place depending on the severity of it when we don't have those experiences but they aren't frequent and they do become manageable in my experience.  I think it is healthier to experience them than to numb out.  We're conscious when we can feel the panic, anxiety, fear or dread and Al-Anon offers tools to include the membership to help with that.  When we numb out - I think we're paralyzed in a lot of ways and not all that conscious.  Might be the difference between responding and reacting for those of us who have been traumatized if we can feel our feelings and notice we don't like the way we feel and use tools versus trying to shut the feelings off and shove them down?