Brief Answer:
Neck most probable cause, but dental issues should be considered.

Detailed Answer:
I read your query carefully and I am sorry about the persistent pain you have been in.

The fact that the pain is not well localized, but spreads from the neck to the ear makes the diagnosis a little difficult.
Given your history of spinal degenerative changes that could be a probable cause, it can cause pain which irradiates in the head, although the tooth perception is not that typical.
Another possibility is a dental issue, either a tooth infection or a dysfunction of the temporomandibular joint.
Another last possibility might be an ear infection although usually the pain is well localized and doesn't spread as far as the neck.

In terms of treatment for all those alternatives you can take non steroid anti-inflammatory medication like Ibuprofen, Meloxicam etc which should relieve the pan. Muscle relaxants like cyclobenzaprine may also help for the neck issues along with physical therapy. In the meantime you should schedule an appointment with a dentist to exclude dental issues. Carrying a soft collar for a couple of weeks can also benefit neck related pain and spasms.

I remain at your disposal for furthr questions.

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Brief Answer:
Read below.

Detailed Answer:
Thank you for that additional information.

If there is local swelling as well, then a dental issue becomes the primary suspect, neck issues do not cause such swelling at that location.
I can not exclude the possibility of a ENT consult being needed, but one has to go step by step, it would be too easy for me to recommend all sort of consults with all type of specialists, I don't suppose that is what you need. I suppose actually the wise thing to do before running to a specialist would be to see your primary physician which might direct you, but I read in your other queries that you are abroad and probably do not have a primary physician I guess.
I believe a dental issue to be much probable with that description, an exam of the area will shed more light and even if the dentist doesn't find anything with your teeth, jaw and mouth, his/her exam findings can provide suggestions on whether there is actual swelling and you need to see ENT for ear infection.

Generally all anti inflammatory drugs have similar side effects gastric ulcer and high blood pressure, but in a young person such as you they are generally well tolerated.

As for physical therapy, if infections are excluded, yes generally it is a specialist such as a neurologist or rheumatologist who prescribes it, however if you have all the documentation about diagnosis and MRI results you can go directly to physiotherapist as he has the needed data for a treatment plan.

I hope to have been of help.

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