@Tella--I have had terrible neck pain as well, along with dizziness and the sense that I just can't be upright for another minute. Turns out the two latter were POTS in action. Have you checked that out? There is a pretty easy way to get a sense of whether that is an issue for you at home.
For me, there is so much going on in that relatively small space--an MRI helped to identify some of the hidden causes, like disc problems, arthritis (which creates bone spurs that can then jut into the spinal canal), stenosis of the spinal canal and of the foramen (holes through which nerves thread). And then not surprisingly, there is muscle involvement as well. Finally, of course--CCI and AAI. So it is a big mess and sorting it out seems to have to happen one piece at a time.
Traction by a PT has been heaven, literally. I feel so good in so many ways after some of the relentless pressure on all the structures in my neck has been relieved. Getting traction from a PT who is knowledgeable about necks will also tell you more about CCI. If it helps, then it is more likely that is an issue for you.
Dr. B recommends over the door traction devices.
https://www.amazon.com/Duro-Med-Cervical-Traction-Physical-Therapy/dp/B000FH19QW/ref=sr_1_5?crid=20LYXEWTFMCSC&keywords=cervical+traction+device&qid=1561167759&s=gateway&sprefix=cervical+traction,aps,141&sr=8-5 If you go that route,
@valentinelynx and others suggest you replace the head cradle with this one:
https://www.amazon.com/gp/product/B00QKNSQNO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
My PT was horrified at the use of these devices--she said: It is not the 70s anymore. Come on! But some people here love them. My PT recommends a supine device, which is far more expensive, unfortunately. I worry a bit about traction if you don't have a pretty complete understanding of what is happening in your neck. Pulling, even gently, on part of it can translate down your spine and do things totally unintended to it if there are problems that have not been identified.
In terms of collars--I have tried a number and none have helped me. That is my particular pathology though (I have disc problems in the thoracic spine; cervical collars brace to some extent on the thoracic, so while I appreciated the lift for my cervical spine, the pressure on the thoracic created other issues). I believe Jeff and Jen and others here at PR have had some relief wearing a collar. This is the one I was told by my doctor (at Center for Complex Diseases) to get:
https://www.dme-direct.com/aspen-vista-collar-cervical
If you want it, PM me. I have a collection of these things that are of no use to me. What I have been told is that four hours a day is the maximum one should wear a cervical collar to avoid losing muscle tone in the neck and putting yourself in a position where you have less to work with in terms of holding up an already heavy head.
Good luck--it is a complicated area and problem, but I think understanding that there is a 'mechanical basis' for a lot of one's issues is hopeful. I do hope you can figure out some ways to get relief as well as to understand what is going on so that you can make strides toward permanent improvements.