It may sound stupid, but how do you actually die in a lucid dream? I tried jumping out of a building, getting smashed by a car, but somehow I don’t die - I can still walk, think and talk. I want to know how death feels in a dream. Any advice?
I never tried this now, where I’m actually exercising LDing, but I remember a dream from my childhood. In that dream I knew that I was dreaming and I was in prison. So to escape I stabbed my heart with a knife. I didn’t feel any pain and I was in a different location (on a grass field to be precise ^^).
Like any other thing, you have to believe it will work. Otherwise it won’t. That simple. 
You can try stating it before attempting, “Doing X will kill me”, and mean the words. See what happens. And good luck 
I remembered groundhog day 
now about your problem-i believe there is another topic like this one
https://community.ld4all.com/t/dying-in-your-dream/12491
I survived the moon falling on my head…
It was weird, as I lost fell unconscious in my dream. I woke up in a huge red crater miles across…