I get night terrors a decent bit due to my PTSD. I have, however, found something that helps me to just about cut the occurrences in half for me. And yes, I do also take amitriptyline as needed for sleep so that wasn't helping my case any before I figured out my little trick to lessen the intensity and frequency of my PTSD induced nightmares. So I know how much amitriptyline can screw over your sleeping mind if you're unlucky.
Now, you may laugh but, if you're a creatively minded type it may be worth a try for ya. What I started to do was do a bit of story based creative work for about 15 to 30 minutes before laying down to sleep. That way I can get my brain into thinking about what I'm working on and the story and environment of that work so, with that fresh in my mind and still brainstorming about it as I lay down, I'm a lot more likely to have dreams about or similar to the subject matter of the story I was working on.
It's kinda like pre-programming your brain for the night, setting your potential thought processes and even potentially some of your subconscious thoughts to a degree (as brainstorming can engage that part of your mental resources as well) on the path for something more desirable to dwell on through the night and thus making the more favorable type of dream more likely to occur since it's fresh in your mind.
This creative works mindset doesn't just have to be straight up storyline writing. It can be a number of things from creating the backstory for a D&D character, fanfiction if you enjoy doing that, visual design of the character(s), role playing, even random thoughts of "what if" can set your mind a bit farther away from the sources of the nightmares. Just make sure it's something enjoyable that you sic your brain on because the last thing you need in that situation is for your brain to bring back a rotting, half eaten dead rat when you need it to catch you a soft, fluffy bunny to provide comfort for you during the night.
Oh, and if you aren't the creative, artsy type, you can also go with the option of watching a show or reading a book that really grabs you and lets your brain get lost in it's story a bit, so long as it's something that isn't gonna cause nightmares worse than the ones you're trying to avoid.
As for the sleep paralysis bit, I get it once in a while. I found that accepting it and using the time to do some meditation or to mentally go through your to-do list for the day as a good use for the time since it's not like you're really going anywhere til your body decides you're allowed to move again. Sleep paralysis is no damned fun to deal with but you can at least make that time where you're stuck laying there unable to move to make some use of the situation.
Of course these are things that help me, but I'm hoping that, even if my methods don't work as well for everyone then, maybe at the least it this info can take a little bit of the edge off or give someone a starting point. Sorry for necroing the thread here but I did kinda feel like I had something worth contributing to this topic. Hope it's a forgivable necroing of a thread all things considered.