It can basically be summed up as: don’t let a certain stimuli afflict my subconscious at all. In my case, it’s heat.
You see, my father liked to keep things at a toasty 75ºF to 80ºF year-long, which was especially noticeable during the winter. As a result, I tend to like warm temperatures as well; but when I sleep, apparently the warmth triggers some memories in me, and bam, nightmares.
I discovered this by accident when I began to leave the thermostat at lower and lower temperatures—currently below 65ºF—and noticed that the nightmares had bled away. When I turned up the heat on other nights, the nightmares came back.
So far it’s been reliable, and it saves on the heating bill as well. But it may explain why nightmares can go up during the summer for me.
I don’t fear falling asleep anymore. Of course, nowadays I work on the novella and study and all that, so I tend to still stay up late, but sleep is always there when I need it.