Currently I've just given up and embracing feeling relatively tired all the time. I've tried side sleeping devices (woody knows backpack) mandibular advancement splints etc.
So hard to tell (I find anyway) to get to a definitive answer
For some people, they don't feel any better but it improves their health.
Did you examine your numbers at all in something like OSCAR? You could get a good idea of how many events you were having at night, and if the CPAP was improving it.
Even if you aren't feeling any better (yet) it could still be helping. You could also have multiple things that are causing you fatigue issues, and maybe fixing only one of them wasn't enough... that doesn't mean that one wasn't also important, though.
The main thing about CPAP is that, and imo almost everyone gets wrong, is that you need to titrate it. CPAP is sold as an Automatic Pressure device, but in practice it doesnt work like that. You almost always need to set it just 1 number below and 1 above your required pressure - more like a fixed pressure device. And getting it working correctly - with all the mask combinations, leaking issues, pressure calliberation, supporting gear like mouth tapes and neck bands - can take months. It is incredibly hard - BUT - it is worth it. The best resource for me has been the reddit to get this right.
The key is to track your saturation everyday with all the small tweaks you make and the only way to do it is using something like the O2 ring.
A friend of my wife suggested a doctor and he said that even though my iron levels were in the normal range, people with restless leg syndrome (which I’ve had my whole life) often have sleep issues and benefit from iron supplements.
Within days of starting taking them my tiredness went away. I went from being tired every day for nearly two years to maybe taking a handful of naps for fun in the last three years. Really life changing.
My PCP didn’t understand why I’d be taking iron, but accepts that it works. My sleep charts still aren’t great. Little to no deep sleep, but CPAP didn’t help with that either.
My experience is that it has a noticable effect about 30 minutes after ingesting. I'm currently taking 100 mg tablets. I had done a liquid suspension, but tablets are easier and more consistent.
If you don't notice a difference in the first few nights, it probably doesn't work for you, but b1 seems pretty inexpensive to try.
It doesn't seem to be like some things where you have to use it for two weeks before you notice a difference; but also there's not much (if any?) residual effect. Maybe I can forget to take it one night, but on the second morning, my spouse will ask me if I've been taking my B1. But, sometimes I do have episodes when I have been consistent, so not a silver bullet.
Annoyingly, this symptom had been discussed with numerous doctors for over a decade. I got zero constructive advice from the medical establishment. In most cases, they even showed disinterest and moved on as quickly as possible. Beyond worthless.
On a lark, I fed an AI a two sentence prompt and one follow-up question, and it was able to piece together data and give me the suggestion with solid reasoning behind why it might work. In less than 30 seconds.
But sleep apnea is really bad for your heart and lungs and does damage to them over time.