Are there particular things that you find soothing that you could set up in your room before you go to bed? I use incense and put a recording of my favorite poetry on repete when I am having anxiety and concerns about nightmares. I get sleep paralisis and used to have horrific nightmares. I realise that those approaches might be impractical for people with different sensory needs, but if there is something that you personally find soothing, try incorporating that into your routine right before sleep. I also take melatonin regularly for insomnia and use herbs like valerian root and passion flower. The herbs have to be cycled, there is a chance that taking the same one for too long can cause dependency, but it is more likely that your body will get used to it and it will just stop working. They are fine for getting through particularly rough nights though. I find that once I break the cycle of insomnia with a few good nights rest I am able to sleep with only the aid of my routine and the meletonin. If you go the herb route do so with guidance from a doctor or someone who knows about plant medicines. I also find reading ghost stories bizarrely cathartic, I guess they are a way of dealing with themes of death in a way that is removed from day to day reality. Sometimes trying to suppress a fear makes it worse, but just saying that probably doesn't help much. I have no idea if any of this is helpful, but I hope you find a way to sleep better.