Go see a doctor and get a prescription for Zoplicone to hold you over and help you sleep temporarily. It's not a great long term solution, but sometimes you need to opt for the short term solutions when you are desperate.
Resolved my horrible PFS sleep problems years ago. Describe for me exactly what you eat and drink on a daily basis leaving nothing out and I'll tell you why you have sleep problems. Go.
As a last resort have you tried phenibut (or even ambien)? Dude I had so bad sleep issues in the beginning, I took phenibut once or twice a week when I was seriously bad dude and could not sleep because nothing else that was natural worked at the time. I know drugs aren't the best route but I got so desperate just to get sleep until I found a better solution.
Also high dose zinc or niacin have you tried those too?
I know it is difficult to implement exercises when you feel not good. There are ways to induce a more para-sympathetic state, and this helps sleep and digestion both. Some people use plants, others use prescription drugs. Then when you are a bit better you can do some relaxation / breathing / meditation exercises.
What help and support do you get in your life? Isthere somebody you trust and that can help you?