My problem is that I wake up an hour after I go to sleep and am up for about an hour before I can finish my night's sleep routine. I'm just putting up with it until I can find a solution. I take a sleep supplement and melatonin, which seems to have the same affect for me as taking a doctor prescribed narcotic.
Trying to solve the problem with narcotics is only a short term solution and addiction is a probability
There are natural supplements, including melatonin, that you can take. They may only have a placebo effect, but who cares if you are able to sleep.
One trick I have tried is a sort of mental feedbacvk. I picture all the bones and joints in my legs, starting with the hip joint. I allow nothing else to invade my thoughts. It goes something like this: I see my hip joint. It has a socket attached to my femur. The femer ahd a joint. In front of it all is a kneecap...etc., etc.
Bottom line: get off the drugs and try something else.
Looks like you're worrying about this a lot. Could it be that you are overanalysing? At night if you expect not to sleep or you worry about whether or not you will sleep your body catches on. I have found that watching particular films/tv episodes get me in the right mood to sleep, I think because it makes me think about something else.... I end up with fascinating dreams but sleeping through. Think about what you do as a wid down exercise, try watching something no too complicated but engaging enough on the tv or reading the right kind of book (maybe something you have read before so it won't keep you awake) for a set amount of time before bed. Once in bed try to think about just books or films, let your mind wander but don't worry about sleep. The miment you think 'why arent i asleep yet' even if you are just about to drop off it will wake you up. keep your mind relaxed but occupied by something simple. This has worked for me most nights the past 2 years since I started doing it every night :)
Sorry if I get off topic, I did read your post but my memory could be better.
It sounds like you've taken a very organized path to identify an external cause, all physical. Have you consider mental? How about dreaming when you wake up in the wee hours? Try to ask that question of yourself next time it happens, an it would be good to write it down immediately in your log.
How about sun light or even bright artificial light during the day, melatonin in the evening?
I read a lot of "bad stuff" about long term use of oxycoden (or similar narcotics) so be sure that usage is properly managed. I do recall you mentioned some analysis along this line, I mention just in case I can offer anything additional.
The bright light and melatonin supplement should not introduce any negative affects, even long term.
I wish I had an answer, that not being the case I send this along as encouragement, and suggest here at the end: no caffeine at all, no time.