Mine used to be awful, but luckily seem to have faded. Very rare I have them now, thankfully.
Things that helped me were having somebody on standby who would be available to talk. I didn't tell them about my nightmares but whenever I messaged them they'd be there, even if not immediately, which helped me feel a little safer. Some practical things I did would be to set myself a strict routine (often less sleep can make them worse, apparently) and when I get to bed, using mindfulness to calm my anxiety, or try to. This only worked the second time I tried it though. I think I might have been in a better place in my life though. A friend let me fall asleep on call sometimes, again, that sometimes helped. I think trying to find a way to soothe the bad feelings and anxiety towards the nightmares is good although I know how damn hard it is. Know we are all here for you
honestly I think nightmares are the worst thing I've experienced and I wouldn't wish them on anyone, so I hope you find a way to overcome them.
Sending massive hugs
Em