Not a downer, mugwort2 - glad you posted here. You might check w/doctor just to ensure all ok, but I also have terrible insomnia as a result of my PTSD. Similar to you, I can get 4 hrs or less a night - for me, it's flashbacks, hyper-vigilance that are usually due to being triggered somehow. Has something happened recently to stir things up psychologically?
What do you usually do when this happens, what works for you?

I think the insomnia aggravates and deepens my depression ("...very deep despair") - might this be what is happening with you (trigger - insomnia - lack of sleep causing more depression and repeat). Hope you get some rest, soon.

Take care

Bolivar