6 Month Old — Nightmares? Night Terrors?

My son has been having nightmares since he was around 2 months old, scrunches his face, makes some whimpering noises and sometimes even cries. All the while, still asleep (until he wakes up from me grabbing him to comfort him).

Up until recently, there has been nights where he is inconsolable. He’s ASLEEP, yet he cries so hard... I would pick him up and comfort him any way I could. Walk around in the dark, sing to him, hum for him, pat his butt, rock him, but nothing helps... At some point he’ll just suddenly stop crying and just look at me with so much tears in his eyes, as if he wasn’t just crying his heart out..

Just now, he was asleep next to me and he SCREAMS. A noise I’ve never heard him make before. Sort of broke my heart to hear it.

Is this night terrors? Is this normal? Is there a way to help with his?