If you knew that you were dreaming during a dream then yes you were lucid, even if it was a low level of lucidity where you couldn’t control anything, the mere fact that you knew you were dream means you were lucid.
Seems like the nightmarish circumstances caused some mental blockage, so you felt that you were paralyzed. It’s kinda like those childhood nightmares in which you’re unable to run away no matter how much you try. Pretty terrifying
But yeah if you knew it was a dream, you were lucid. Congrats!
However, lucidity doesn’t automatically mean that you can control the dream. It only means that you’re aware of the situation you’re in, regardless of how much control you have over the dream.
I agree you were probably lucid. You will just have to work on your dream control a bit. Hopefully the next time you have a lucid dream it won’t be in a nightmare and you will be able to explore your dream world a little more. Once you get more experienced with lucid dreaming nightmares will be no problem to deal with. I think the reason you could not move was you had no idea what was going on since you never experienced lucidity before.
Good luck on your next lucid dream. Yes you can have more LD ‘s if you want.