I'm not any sleep specialist but for a Doctor to say sorry can't help you, I think it's time to see another doctor. If your not able to demand to be referred to a sleep specialist and or a Neurologist, you need more professional help.
Good Luck with it, not sleeping is sucker I'm not the best of sleepers but nothing like your going through.
Check your vitamin D levels with 25OH vitamin D blood test. Low D and low magnesium cause cause insomnia.
You want you D levels above 50ng/mL. You can supplement with D3 and magnesium