It's more of a conversation that I'm willing to have with someone to, in part, see where they're currently at and what might be best to focus on first - than putting general knowledge out there, which will require a book to adequately/fully explain everything as there are many interconnected factors. To note, I'm not a doctor and don't have a medical degree.
I can say that there are non-medicative practices, along with diagnostic tools available to show concrete evidence relating to showing problems, that are transformative. The difficulty can be that if certain issues are not dealt with in parallel, or in a proper order may prevent/limit/block another therapy/practice/treatment from being beneficial/giving permanent improvement - that otherwise would be beneficial.
1) There's removing agitations from your physical body - in part, starting by getting a food sensitivity test (food panel) to check for up 184 foods that your body may be negatively responding to; also cutting out certain foods that may not show on these tests but may greatly impact you - like do you eat wheat or potato (sweet potato is fine)? Likewise, vitamin D3 liquid form is also good to take, as most of us are lacking it - 5000 to 8000 UI is good for most people, taking an initial 15-20k UI per day for a few days to load up; vitamin D3 is a steroid.
2) You/everyone should also get their hearing checked for imbalances, which can be used as a diagnostic tool to know what is going on; the brain/mind is a system of homeostasis, so it should be able to balance out to hear frequencies at even decibel levels in both ears. There's a sound therapy you can then do to unlock these behaviours, developmental blocks/delays - and resulting imbalances in sensory systems and how that can impact a person and their thinking/behaviours; this can also unlock and allow other sensory to balance out, that may be hyper- or hypo-sensitive. I know on the surface it can be difficult to believe that a sound therapy (listening to specially modified sound/the way its output) could be "magical" or so transformative, however I have my own personal experiences with such - and observing others rapid improvements. There is research as well.
3) Likewise, there's breaking down any ego mind coping mechanisms that may have solidified deeply over your lifetime - since childhood that could be causing a depressed state, or anxious, or other; ego dissolution is another term being used for this, which can be achieved in a few ways, some ways less or more rapid than others - like Ayahuasca ceremonies.
Relating specifically to sleep, it could be any amount of the above 3 influencing/impacting it enough to cause problems, or it could something in your living situation and environment as well - consumption of caffeine (stimulant) or alcohol/weed (depressants), it could be too much noise (or you're hypersensitive currently) - it could be a buildup of emotional . It could be too much energy built-up by not getting enough movement during the day or a few hours before bed.
It could be a weight issue as well or something like sleep apnea (which could be caused by or worsened by any of the above). It could be that you're trying to fall asleep when your body doesn't naturally want you to fall asleep, and then pressures from your day-to-day life of when you're expected/expecting to be awake are the problem/difficulty; the Ayurvedic clock can be interesting to look into to learn about these cycles better.
Also to point out that different medications may interfere with allowing a system to reach its normal, non-dis-eased and balanced state, once trying these treatments/practices. For Ayahuasca ceremonies for example, you shouldn't be on certain medications for at least 24-48 hours before the ceremony - different shamans have different guidelines they follow - otherwise it can be unsafe. If you eat wheat regularly, you may actually be addicted to wheat, which may be difficult to stop eating - otherwise you'll get more and more agitated because of withdrawal (another specific reason why you may have trouble falling asleep); Ayahuasca is showing to be good at breaking addictions.
Regarding your last sentence, from my experience the majority of doctors are terrible at critical thinking. I realized they are selected primarily for their memorization skills via testing, and not critical thinking. Indoctrination of old, stagnant knowledge via current academic systems, and human error are the crux of the problem.
I realized I didn't actually mention underlying problems I encountered. As I child I would have been considered to have Asperger's - however I never was formally diagnosed, it wasn't really a thing back then. I was hypersensitive - though I didn't realize it at the time - it was only after medications caused me to become severely hypersensitive to sound (hyperacusis) that I realized sound was an issue. It turned out I had developed a hearing imbalance due to painful ear infections when I was a child - primarily in my right ear; it's not the hearing imbalance itself that is the problem, it's a tool to show signs of function. Likewise, when I was 5 or 6 years old I had an painful injury to my right big toe pad - which later on I realized my ego mind had created a coping mechanism to block me from that pain and/or from the emotion of the pain, and then my development continued abnormally with that block; until I did a number of Ayahuasca ceremonies which broke down my ego mind and its coping mechanism, reintroducing me to intolerable levels of pain from many sources. Through trying different healing practices I had been doing elimination diets relating to food, and eventually did food sensitivity testing, allowing me to refine and remove what foods I could eat - and by removing all of those foods, I would feel much better, and then introducing just one again allowed the contrast for me to realize just how much pain it was causing me in my GI tract. Acupuncture was another way to get energy flowing again properly. Yoga was another way getting my body healthier, of developing self-awareness by putting pressure on the systems that signal pain and such. I'm probably missing a few things, a bit tired now from writing. I should include the tipping point related to physical pain, and that lead me eventually to exploring and finding Ayahuasca ceremonies, is that 5+ years ago - the pain from LASIK eye surgery really fucked up my nervous system: a strong tension started down the right side of my neck, and my balance on the right side became notably worse; I had been practicing yoga for 5 or 6 years by that point, so I was very familiar with single-legged balance postures.