Have you taken Melatonin? That is the sleep hormone the body produces, it isn't a drug, you can find it in the vitamin section. Definitely try that first as it is pretty much harmless. You might also try total sensory deprivation depending upon what the exact cause is, that supposedly helped some people with a prion disorder known as Fatal Familial Insomnia. But it sounds like your problem is serious, so the only other contribution I can make is to say that Propofol was the drug Michael Jackson used for sleep, and died from. It is an anesthetic and obviously dangerous, and hinders REM sleep in coma patients, but is worth a try if nothing else works.
Taxes. Laundry. Church.
Ummm...ask a professional.
Only your doctor or pharmacist can determine this, due to your health history.