Have you tried Corydalis in combination with one of these? chamomile, valerian, hops, passion flower, lemon balm and catnip.
Corydalis has been shown to provide pain relief and promote relaxation.
If you still had apnea, I was going to suggest this,
Sleep on your side or sitting up rather than on your back. You may want to sew a couple of tennis balls to the back of your sleepwear or put pillows behind you so you stay on your side.
Use an air humidifier at night.
Raise the head of your bed by placing bricks under the headboard.