Frozen in fear.

So sometimes when I'm asleep, it's like I'm getting ready to scream, but I can't let anything out because its like I'm frozen in fear, so I just breath fast & let out a moan & I'm asleep when tht happens but I'm aware tht I'm doing it, & Idk if I'm doing it in my dream or if I'm actually doing it in reality ? The thing is tht Idk what kind a dreams could be causing tht because I don't remember any dreams because sometimes tht happens. Does anybody else do tht too or is it just me ? I hope its not just me & I hope tht this makes since to you guys because it made better since in my head.