Crispapple, one thing that really helped my daughter with her horrible ptsd nightmares was reframing them immediately when she woke up. That is, talking out or writing out an alternative ending to the dream. So if she was being chased by one of her sunsets and he caught her in her dream we would reframe it that when he got close to her she turned and punched him and then flew away, free and safe.
I don't know why, but research has shown this kind of reframing nightmares can help make them less scary and less frequent. Might be worth a try