Hi, I wrote the below post a while back but you never responded to the thread so don't know if you saw it. The Trigger point therapy workbook by Clair davies outlines very specifically the muscles that can cause ear fullness. It is more likely a muscular issue than a nerve issue. The book isn't that expensive and worth the read. I am reposting the thread I wrote to you. The fact that elsewhere on the net you mentioned eye floaters, blurred vision and a spinning sensation makes me wonder if you are experiencing vestibular migraine as I mentioned below - those are all potential symptoms along with full ears.
I did a few months with that full ear hell and know where you're coming from. Also did a fair bit of research in to it.
When it comes to full ears there are a few things that could be causing it.
As your doc said - mucuslar problems in the neck/jaw refer to the ears and can cause the muscles in and around the ear to go in to spasm. The answer to this is stretching exercises. Sometimes, if you clench your teeth at night a nightguard will work. I do and I used a night guard called an NTI which was extremely helpful, allowed the muscles to relax. If you are a clencher or a grinder it could have contributed to the neck problems you experienced. There is also a book called the Trigger Point Therapy Workbook, which teaches you how to massage trigger points to target certain areas, including the ears. Look up tensor tympani syndrome and tensor velor palatini on the net - those are the muscles you are dealing with. Also check out stretching exercises for the neck. If you are in a financial position to do so I would get a good physio to work through some stuff with you.
Another possibility is that the headaches are contributing to your symptoms. Neck problems are known to cause migraine - (you don't need to have the auru everyone has heard about) And migraine, believe it or not, can cause this sensation of ear fullness and also dizziness. There is a condition called vestibular migraine which causes dizziness and can cause ear fullness. A number of people on this board have it including me. The answer to this is to treat the headaches with a daily migraine preventative.
Menieres disease can also cause ear fullness - but that's highly unlikely in your case - as this all started with a bad neck.
You have been checked for eustachian tube dysfunction so it isn't that.
Labyrinthitris/vestibular neuritis can also cause it - but again, because of the initial neck problem it's very unlikely to be that.
My guess would be tmj related problems or migraine - or very possibly a bit of both - the former driving the latter.
My guess with you is the answer is to work very hard to stretch daily, do it diligently, possibly use a nightguard. Possibly treat the headaches with a migraine preventative - you would need to see a neurologist and get one prescribed.