I take a pain pill for my arthritis...does a decent enough job I suppose but despite the "may cause drowsiness" warning on the bottle I discovered that I am in the 0.1% of the people that it can cause trouble sleeping. If I take it after 6 PM I might go to sleep okay but in 2 hours I am wide awake and it's impossible to go back to sleep...it causes insomnia in some people and I drew the short straw.
All medications come with some sort of baggage for some people and how that baggage affects us is widely varied.
Anytime I see a side effect of nervousness I usually will see a side effect of effecting sleep as well.
Damned if you do and damned if you don't when you take a pill for your nerves and a potential side effect is nervousness.
Kinda like me....let's see...I can not sleep well from pain or not sleep well from the medication used to treat my pain.


I won't be in as much pain when I am up cleaning the house at 2 AM because I can't get back to sleep.

I mention all this because I know you want all your problems to be just related to the OSA but the cold hard fact of life is that there is a good chance you have more than one thing going on that needs to be addressed. Doesn't mean we don't keep trying and just give up....just means we keep turning over rocks looking for solutions. I still work on my pain as best I can and have tried various other meds over the years to help with pain that might not cause insomnia problems. I won't give up. I long ago got my OSA therapy side of things optimized and I am good with that but even that took me almost a year.
Be patient....99.99 % of the time we just don't get lucky and get a quick fix for our problems. Those that do..they don't know how lucky they are.