I walked about 25 miles one day looking for keys I thought I'd dropped on the side of the road. I didn't find them, but I ended up falling asleep on a hardwood floor without any cushioning or covers, and I slept really well.

So exercising to the point of exhaustion every day could work. But that's hard to do, especially when you already feel like shit from insomnia.

Have you tried drinking yourself to sleep? I usually feel great the morning after a good blackout (until I have to start paying my friends to never tell me about what happened).

I'm in the same boat, and physical exhaustion (not just moderate exercise) is the only thing other than drugs that reliably puts me to sleep. But it's not easy to maintain, so that's probably not a solution unless you already exercise a lot and can just push yourself to overdo it.