This is getting really complicated.

What I see is this:
You had many many invasive treatments. Starting with endoscopes down your neck/throat.

You had 3 epidurals....needles in your upper spine.

You had MRIs...more than one with contrast? Injection of foreign dyes into your blood.

This is all something to consider.... there is no free lunch. Every time a needle goes into you or a device goes into you there is risk of infection or damage.

Damage to the dorsal roots may not heal in some people. This may be viral as in Herpes Zoster, or other viral infection. Some people lack the ability to heal nerves in the dorsal root. We have a paper on here in more than one post illustrating that.
If that dorsal root is not working properly...putting a cream or gel on your shoulders, etc is not going to work. The pain is not generated from your skin back there. It is along your spine higher up.

The special MRI that en bloc describes may show this damage.
Ganglioneuritis.
http://neurotalk.psychcentral.com/post758457-1.html

If this turns out to be your problem, the seeing an infectious disease specialist who can prescribe the proper antivirals may help. They may also do the special Igenex Lyme testing. Or something else we don't see on these boards.

It seems you have exhausted most avenues now. Your unique doctor interventions may have caused your issues, or you may have some obscure infectious process that hasn't been identified as yet.

I don't think amitriptyline is your problem. The old lists, show it as an axonal damaging drug...but time has not proven that at all. It might be a coincidence of treatment that was not taken into account when studies were tabulated. Millions of people have used it since... and it never shows up as a trigger for PN in those low doses now. If it were a culprit, millions of uses, would generate more papers and interest.

There are also other possibilities... and I am thinking perhaps Thoracic outlet syndrome. But you don't have pain or issues down your arms do you?

I will say this. Your cortisol is highest in the morning when you feel better, and falls as the day progresses. The fact that you can sleep with this problem is really rare. People with significant pain cannot sleep. So that is a hint, I think to follow.

I don't know where else you can go... but I think viral=infectious disease and therefore that would be another stop for you.

I am sorry, there is not much else we as laymen can do for you. Your history is complex and medical and unique to you.