I don't have quite the trouble you do but I do have some. Mine is mostly stress right now; 60 hours a week at work plus a cross-country move.
Ambien has always worked wonders for me and its getting cheaper. One of the things that I found out (mostly due to stress and cigarettes) is that my blood pressure was insanely high, like 180/120. I got on some blood pressure meds and I'm sleeping a LOT better.
Sometimes I medicate with a six pack and get right to sleep, but then I always wake up at 4am.
First of all try to identify if there is something external that is keeping your mind working. At my old job (running an auto repair shop) I would work all day and into the night with 6000 tiny little things to accomplish, then I would try to sleep and all I could do is race my mind with "did I order that part? did I remember to set the alarm at the shop? how are we going to fix this car that is giving us fits?"
If its something like that, find a good way of downloading your brain by making a list. I used google docs to keep it portable. If I write down a list, then I have multiple lists that get left behind, etc.
If its something chemical, try herbal stuff - chamomile, weed, a snip of scotch, etc. For a while you might have to break out the big guns like Ambien but I'm not a big fan of drugs. My naturopath wisely said to me once, "you don't get a headache because of a lack of Ibuprofen in your diet." In the same fashion, you aren't having trouble sleeping because of a lack of Zolpidem Tartrate in your diet. Try identifying and fixing the cause, not the symptom. I'm a highly introspective person, so identifying the cause comes easy for me, but taking steps to fix them is something I have trouble with.
I do, however take blood pressure medication. Instantly quitting smoking isn't easy, and my job (while stressful) is a means to an end. Once I get the move completed, I won't have nearly as much financial stress forcing me to keep a job I dislike, so in my mind I'll have more freedom. Hopefully that will fix the cause of my symptoms and I can stop treating them with prescriptions.