I feel you. I have PTSD so I definitely have days like that too where I am in constant fear. What helps me in those times is to get out of my mind, bc my mind is such a scary place. Curl up under the covers, or wherever you feel most safe (or least unsafe), plug in some earbuds, and watch your favorite show. Taking a freezing cold (and I mean freezing) shower helps too. I have a whole slew of physical and mental coping skills, and I'm happy to talk any time.