Thank you. what do you mean by "What's more important is what you do during the day." please explain
It can take a few weeks to months for your body to get used to not getting anymore caffeine. You must already know that chocolate also has various amounts of caffeine.
It sounds like you need to follow-up with your sleep doctor to further optimize your CPAP usage. I agree, good sleep habits are important, but you may be better served with a formal sleep-hygiene program such as cognitive behavioral therapy. See Dr. Gregg Jacob's insomnia forum for further details for his online program. It can also help with CPAP users.
There are so many recommendations for natural sleep aids, but none work consistently for all people. What's more important is what you do during the day. This is why a formal sleep hygiene program is so important—without this, no sleeping pill, herb, or supplement will help you sleep.