Our sleep cycle, Circadian Rhythm, is part of our Autonomic Nervous System. It regulates our temperature, heart rate, breathing, sleeping, appetite, etc. Things we don't have control over. They are Automatically done for us.
I think many PWMS have broken Autonomic nervous systems.

JMO
We can try to change, repair, medicate ourselves, but I don't know anyone who has managed to take control back from their brain.
Plus, so many medications we take can mess with our sleep habits. Even a daily nap, lack of activity, or a rainy-gloomy day, can alter the evening sleep cycle. Then it becomes a habit, which is so hard to break.
I wake with my legs/feet burning every two hours.
We understand. Pain can do it. I hope you feel better and get rid of that pain. Perhaps that will help you. Good luck K