Books like “Why We Sleep” and podcasts like Huberman Lab are kind of like a junk food version of science: They deliver some bits of information that can be helpful, but they’re so coated in stretched truth, overconfidence, and stories crafted more to sound good than to be accurate that it’s not really accurate science material.
In a case like yours (difficulty sleeping) that might actually be fine, to be honest. A lot of people find relief from simply feeling like they understand a subject, rather than from having absolute accuracy of information. The confidence begets a feeling of control, which diminishes anxiety, which indirectly leads to better sleep.
These podcasts and materials often follow a pattern of suggesting some specific protocol based on loose interpretations of some underpowered study. The actual power of these supplements on routines is almost always much lower than the host says (Huberman is one of the worst at this) but the confidence with which the protocol is prescribed is often enough to convince people that it will work. The protocols and supplements turn into rituals and routines, which are cues for sleep, indirectly establishing a healthier sleep cycle with cues for relaxation.
On the other hand, some people get more anxious after consuming this material because they feel like not sleeping well is killing them, which creates more anxiety, which then worsens sleep.
I’ll let you decide which category you’re in.
For actual material on the subject: Sleep science and research isn’t as much about practical lifestyle tips as you might expect. The material that would be more helpful, practically speaking, is to pursue therapy-like modalities and relaxation techniques. You will find much more material about practically improving sleep from the therapy angle than you will from reading deep science on sleep architecture.