Thanks for your reply and I can fully understand what you are going through and how it effects everything going on in your life !
I am no expert and can only talk about what happened to me, I guess I was the opposite to you in that I went from the oral device to the CPAP and while the CPAP is not perfect at least it allows me to get the sleep we all need!
Just a question, how did the CPAP cause your neck problems if you don't mind me asking, it is because you were sleeping in different positions ? I have bad upper neck and back issues and I usually slept in what I now understand is the featal position, which is bad for your back so I have been trying to sleep as much as possible on my back with a low pillow not one that pushes your neck and head up - along with massage, stretching and not sitting for too long a periods I am hoping this will be the cure that I am searching for with my neck and back issues. I am just wondering if the above might solve yours too, from all my research all of the above suggestions are what everyone reports as being the only way to fix upper back and neck pains ?
As for the oral devices, I am really against them, it is not natural to lock your jaw into a different position for 8 or so hours every night, if you think about it for any amount of time you will realise that too. If I was to lock my leg into a position and hold that for 8+ hrs a night I am sure I would wake with muscle aches and hip problems too I imagine. I know they work for some but not for me and by the sounds of it not for you either !! For your muscles to be that tight that they are effecting your hearing with tinnitus that must be very tight !! I would suggest massages for your jaw, neck and upper back muscles and you will need a lot of them weekly for a fair while I would say !! After that I would drop them back to every other week and then maybe monthly for a few months - but in the mean time I would stop wearing that oral device - that is what is causing the muscle tightness and you can tell that because your back teeth do not touch.
This is exactly what happened to me and I eventually had to have braces fitted to my lower teeth with an anchor point on my top back teeth to pull my lower teeth backwards where they once were before using the oral device. For a chiropractor to say you will get used to it is great for him to say, but there is no way of knowing how long that will take you - it could take years to for your muscles to get used to it AND THEN you still have the problem that your front teeth are taking all the pressure of you chewing your food every day. I was told and completely agree with two dentists that if you continue on like that, that my front teeth would eventually crack under the pressure !
My advice and this is not coming from anyone with a degree in anything, just someone who has been in your position - is to get rid of the cause of your problem. If you had a thorn stuck in your finger it is going to hurt, sure in a heap of time your body might get used to it and heal around the thorn, but why not just pull the thorn out and let the body heal the damage that has been caused?
You are going to need braces to get bite back to how it was beforehand also, sorry to say - I only had mine on for 2 months if that is any positive for you to take?? Go back to the CPAP and try to find a mask that makes it more comfortable for you to sleep, this will allow you to get the rest you need, will take away the pressure that the oral device is causing and the braces will take your teeth back to where they are supposed to be. I would also talk to your dentist about the costs for braces, mine said before I had the device "no this will not change your bite" so 2 years later when I was back in the chair and he could see that yes it had in fact changed my bite he was in the wrong ! So I only paid about $40 out of pocket for my braces and he should be lucky that I did not complain about that - the braces were so uncomfortable it was not funny - but it is only for 2 months !! haha
Hope this helps you a little, like I said by staying with the oral device it is only going to keep the pressure, tension and pain going for a long time I would say ! Plus your teeth will start to crack under the pressure of your bite - so how can this be a solution from a chiropractor and dentist to suggest ?? Common sense says fix the cause and the problem will go surely ?
Hope that this helps your out and others in the same position, CPAP is just continual air flow, it can not cause any ongoing problems, it is just a comfort thing that is going to be individual to each of us at to what we like and prefer - once again just my take on it all !