Although I don't know the extent of your situation and what you've tried to soothe yourself, I empathize. Nights are hard for me too, since it's dark, quiet, and I'm by myself.

To distract myself and get away from negative thoughts, I play soothing/neutral music or listen to ASMR videos (especially the pampering role plays). Sometimes ASMR is like having a caring friend beside me, someone who can take me away from a vicious cycle of endless thoughts as I try to head towards sleep. Some of the soothing videos also put me to sleep more easily than if I were lying in the silence, listening to the jargon inside my head.