I am looking for the medical/psychological term for my experience:when my husband speaks to me, he is harsh, critical, domineering, demeaning+i can feel my body shut down- heart beats faster, brain gets foggy, i get nervous. what is the name for this?

The term, stonewalling, is used when one shuts down after being bombarded by negativity. It may also be called emotional suffering. It's a shame that your husband behaves in such an unreasonable, cruel, & obnoxious manner.

A so called "fight or flight" reaction matches your description that is reactive to stress as described. Would suggest starting with family counseling.