He just won’t calm down

My son wakes up between 4-5am and won’t stop screaming/ crying and thrashing himself untill about 6am. Idk what to do. Nothing helps. He won’t take a pacifier when this happens. Not a bottle or the breast. We try to hold him but he pushes and kicks us. Sleep sacks make him panic. We tried a nightlight, calming sounds and lullabies. We see the doctor tomorrow. I’m just so tired and worn out. He acts this way too when waking up from naps. So far the only thing that snaps him out of this state is when his big brother comes to see him otherwise we just wait it out.