I'm going to be a bit morbid here, but of all the diseases or mechanical ways to die, which would be your LAST CHOICE if given a preference. Dead last, so to speak.
For me, it's any situation where you know you're fucked but can't do anything to stop the inevitable.
Give me instantaneous death where idk what happened or a slow progression of disease where death would eventually be a welcome relief. It's the in between that freaks me out.
There’s a horror movie called The Sacrament and in it one of the characters while totally conscious is injected with a slow acting poison against their will and had no options to counteract it or whatever. I don’t get freaked by much but that really fucked with me. Knowing that you had 30 minutes left and there was nothing that could be done is horrifying